To repair a vehicle’s rear window, purchase a do-it-yourself repair kit, such as Fix-A-Windshield or Permatex. Position the vehicle so that the rear window is not in direct sunlight and is cool to the touch.
With the Permatex kit, use an alcohol pad to clean the area of the crack. With a push pin or needle, clear out any debris and loose pieces of glass, and then use another alcohol pad on the area. Affix the round double-sided adhesive found in the kit around the area of the crack. Remove the other side of the backing, and attach the stand for the syringe to the exposed adhesive.
Squeeze approximately 3/4 of the resin into the cracked area. Push the syringe’s plunger all the way in, and secure the syringe into the stand to create an airtight seal. Pull the plunger back until it aligns with the indented mark, and then lock it in place by twisting the plunger. This draws out any air bubbles in the resin. Wait 10 minutes, and then remove the syringe.
Seal the syringe in place again, and lock the plunger into the lower setting. Wait an additional 20 minutes. Remove the syringe and adhesive ring, move the vehicle into sunlight, and apply several drops of resin to the crack. Cover the area with the provided plastic square, and push out any visible air bubbles. After 15 minutes, remove the plastic, and scrape off any excess resin using a razor.