I haven't had good luck with the stripe application gel... Windex window cleaner is another product some use. I now offer a stripe application fluid that dries quickly and yet allows a good repositioning window. It will also dry through the vinyl for trapped bubbles and leaves no residue. Also it's pre-packaged so it's not going to have any contaminates or trash in it that you might get mixing soapy water yourself. I've read of people putting stripes on dry, but this method allows no room for error in positioning and any bubbles will be trapped air that can only be removed by pin pricks.
1. Do a dry test fit first, verifying that the wheelwell opening will be properly centered. I had a bad set once that wasn't! Also verify that the door aligns correctly with the quarter panel.
2. Clean the area to be striped first with a water-based cleaner. Follow with wax & grease remover. Last, wipe it with a tack rag just as if you were going to paint it. This ensures that you won't trap any dirt specks under the stripe.
3. Peel off the backing material and apply stripe application fluid to both the stripe & car one section at a time. Be careful not to touch the backing or get any dirt on it. You can start a corner, wet it with solution so your fingers don't stick to the adhesive. Also be sure your hands are clean!
4. Carefully position the quarter stripe section first. It's advisable to have a helper! This is a large stripe section that's much easier to handle with 2 people. (Reward helper with beer AFTER the stripe is done!) It should have an even consistant gap around the wheel opening. The top edge of the stripe to the top quarter line should be about the same distance as the wheel opening to stripe gap. These two references should get the stripe where you want it.
5. When you're POSITIVE you have it where it belongs!...Squeegee the stripe thoroughly with the carrier sheet in place. Once the carrier sheet is pulled, squeegeeing can scratch the vinyl. Start at the center above the wheelwell and work forward first, then back toward the rear. Before getting all the way to the rear, ut a relief cut from the lower rear corner of the side marker hole downward at an angle to the rear of the car. Some people prefer to cut it horizontal, but originally it was at an angle. The overlap should be with the bottom part of the cut tucked under the top. Don't cut the side marker light hole at this time; wait for a couple days until the stripe is well dried. Cut an X from corner to corner and fold to the inside.
6. Allow plenty of time before pulling the carrier sheet. Too soon and you risk pulling up the stripe and trapping air under it. To save time, just the very front of the stripe can be peeled back to see the stripe edges. Then the door stripe section can be installed while waiting for the quarter section to dry.
7. Once you've pulled the carrier sheet, rewet the edges where the stripe bends into the jamb. Use a heat gun to warm the flap slightly as you work it down. It will take a little time to dry the solution, but it prevents causing a wrinkle from it sticking too soon as you fold it over.
8. Do the door section next, positioning it such that it aligns perfectly with the quarter stripe. Note that forward & backward movement will change the width vertically and affect the alignment with the quarter panel stripe section. Also be careful to position so the lower line is in a straight line with the respective quarter panel stripe.
9. Most important!... only use the heat gun for the edges mentioned... any remaining bubbles are trapped solution and will come out on their own. It can take anything from a couple days to a couple months depending on how much sun it sees, humidity, temperature, etc. DON'T PANIC!!! Be patient and don't mess with it!
10. Stand back & admire your handywork. Be careful to not twist your spine as you pat yourself on the back!