Help - DIY

Be patient it could take a whole day to apply the stripe to the entire car.
Make sure you have plenty of material available to stripe the entire length of the car at least twice and add some more. Include enough for a hardtop, even if you haven't got one. (Better to much than be left 1" to short.)
Very important
When filling your large bucket with water add a few (2-3) small drops of dishwashing liquid. Do not make it too soapy! as this will not allow the stripe to dry properly to the surface of the vehicle. Only a few soapy bubbles should be visible on the surface.
Test Procedure - Cut a small piece of vinyl a few inches in length. The general application process for the vinyl stripe material is to have the surface of the car extremely wet as should the vinyl. Using your sponge soak a section of your MX-5 with the soapy solution. Some people use a spray bottle to put the mixture on both the car and the vinyl. (Spraying both sides of the vinyl and the paint work) Also dip the piece of vinyl into the bucket to set the surface. Remove the backing from the vinyl and apply the vinyl to the surface of the car. The vinyl should be able to easily slide around on the surface . Once satisfied with the positioning, take a straight-edged surface such as your credit card and gently wipe the surface of the vinyl in an upward diagonal fashion (away from you). This should remove all the water and any air from under the surface. Don't press down to hard with the edge that it digs into the vinyl.
Now with your dryer on low-heat, begin to apply heat to the vinyl whilst simultaneously using your wet sponge or fingers to smooth out any water  or air bubbles still underneath the vinyl. If you find any dirt or dust particles still underneath the vinyl Don't panic! You can still lift the vinyl, wipe away the dirt with your wet sponge then repeat the above procedure.

SAFETY WARNING - 'RISK OF ELECTRIC SHOCK' OR 'DEATH' as ELECTRICS AND WATER DON'T MIX. Find someone with dry hand to help apply the heat.

Step 1 - Wash your car  well to remove all traces of road dirt, flies and bugs etc. I also found that it is recommend that if you apply a thin layer of wax, this can help the removal of the vinyl in the future should you ever need to replace a piece or remove it altogether. 

Bonnet Application 
Step 2: 
With help, apply a long piece of masking tape equal distance from both sides the full length of the bonnet. If you are have a single stripe this will be the center line, so you may need to work out an offset measurement for the edge guide. If you are having 2 stripes, this will also be the center line but also the gap between the 2 stripes. This MUST be straight!

Step 3:
Un-Roll the vinyl across the length of the car to get the rough lengths required. Cut the vinyl with a good few inches extra. This extra will be used to wrap around the edge of the hood. 

Step 4:
Soak the hood of the car with the soapy solution. Now soak the section of stripe you just cut before removing the backing. With help, remove the backing of the ' Controltac' vinyl and place gently on the hood of the car. DO NOT crease or fold the vinyl. It is very thin and susceptible to creases. If you're patient when removing the backing, this can be avoided. The vinyl may well apply with wrinkles, wrinkles and creases are not the same. The wrinkles will be smoothed out with the credit card. 

Lay the soaking wet vinyl stripe on the left (or right) side of the tape matching the edge of the vinyl to the edge of the tape. This should ensure a straight stripe and equal distance between the stripes. Once you are happy with the positioning of the stripe, your 2nd pair of hands will need to holds down the stripe to keep it from moving, while you wipe away the excess water from under the stripe with your credit card or sponge. When most of the excess of the water is removed, begin to apply heat with the blow dryer while continuing to work the bubbles from underneath the vinyl. 
When you are satisfied with the final position, (check the stripe positioning from a distance, it's easier to see if it is off center) fold the excess stripe around the edge of the hood and apply heat to remove any water.

Important Note! - Do not continue to use a squeegee or credit card as this will risk stretching and/or tearing the vinyl when heat is applied. The heat will soften the vinyl and soften the glue on the back. The only best way to remove the bubbles from underneath the stripe is to use a soft wet surface such as your hand or sponge. It is very important that your fingers stay soaking wet. Dry fingers will tend to pull on the heated vinyl. (Extreme example - soak a sheet of A4 paper, now dry your hands before rubbing your fingers across the surface. Now repeat with wet fingers)

Step 5:
Repeat Step 4 for the other side of the masking tape.

Front bumper application
Step 6:
Measure the length of the bumper with the vinyl and cut to the required length. It will need to match up perfectly with the line of the bumper so that it sits just inside the rubber lining between the bumper and the bonnet. Mark the center line with masking tape as before. Repeat the same procedure as shown in Step 4. When applying the vinyl push it into the groove which runs around the bumper. This may take quite some time to smooth out  with your wet finger and blow dryer. Mk.2 MX-5 (99+) will not have this problem as the front bumper is smooth. Take your time also when applying the stripe to under-portion of the bumper. This will also want to wrinkle and crease because of the curves of the MX-5. As you apply heat, this becomes easier as the vinyl will be able to stretch and apply itself underneath the bumper.

Boot lid and rear bumper application
Step 7:
Using the same methods as  above, use the masking tape as your guide down the middle of the rear deck-lid and rear bumper. Repeat the steps above to ensure proper application.

Step 8:
The rear bumper panels. this final step of the stripe application can be a bit of a nightmare. First there is the number plate section and then the rear bumper, the curves at the bottom, makes each stripe bend inwards to meet at the bottom of the bumper. There are two options. Do the bottom of the bumper with two pieces of vinyl instead of one or, apply enough heat to the vinyl allowing you to stretch the vinyl enough that it maintains a straight line over the bumper. This is very difficult, which is why this section is best done last. Too much heat will stretch and possibly tear the material. Try a few test pieces to determine the amount of heat required. This is why you need more than the minimum length required.  If you have properly applied the top of the bumper, it should be drying while you work on the bottom portion. Gently pull down the stripe material in the direction away from the masking tape just enough to keep it straight. With the right amount of heat the material will stretch into position without a hitch. You can now gently work out the air and water bubbles.

The Hard Top
Step 9:
The hard top. Follow the same procedure as for the bonnet. This step could be done either first or last as the stripe/stripes could be lined up across the full length of the car.

Step 10:
Allow at least 6 hours for the stripe material to dry and to allow its adhesive to stick to the surface properly.

Step 11:
Allow a few days before washing and waxing the car again.

Approx. lengths required to stripe a MX-5 are: Bonnet  =  1100mm Front top of window  =  100mm Front Bumper  =  500mm Bottom section of bumper  =  200mm Boot (narrow section) =  150mm Boot Lid  =  650mm Number plate section  =  350mm Rear Bumper  =  500mm Hard Top   =  1000mm Hard Top below rear window  =  150mm Total = 4700mm / stripe  (suggested absolute minimum length for each stripe would be 5 meters) Stripe thickness' Guide Single Stripe  -  1 x 250mm or 300mm wide Dual Stripes  -  2 x 200mm wide with 50mm gap Triple Stripe 2 x 25mm + 1 x 250mm (Total should be no more than a standard number plate)