How do you remove factory window tint
 

The rear window tint on my '86 951 has bubbles and or waves that make looking through the hatch (using the rear view mirror) difficult. How do you remove the factory tint without damaging the defroster grid? Steam, heat or a careful razor blade?

It's not factory tint. It's after market. Get the soap based plastic film remover and use and old credit card to scrape with. If you use anything sharper you will damage the heater grid on the inside of the rear window.

i do this;

1- wet the outside of the glass with soapy water and then cover it with black trash bags to help it soak up heat from the sun.

2- spray ammonia on the inside of the glass, covering all the areas that are covered with tint. then, lay a black trash bag over it to help keep the ammonia from evaporating and let it soak in (the bag should stick to the glass).

3- let it sit in direct sunlight for a few hours to get it real hot (this is why black trash bags are better)

when you come back outside and remove the trash bags, the tint should nearly fall off by its self. glue and all. although there may be a little residue left that you can clean off with a razor blade and a steady hand.

According to the options on the delivery ticket it's a factory applied tint. Being 20 years old it may not be the original factory tint. I'll give the ammonia trick a try. But it's getting harder by the day to get good sun in upstate NY

Factory tint is in the glass NOT on the glass.

The factory "tint" option referrs to the little blue-ish strip of gradiated tinting at the top of the front windshield.

Just looked at the original window sticker. There is a line item for "Window tint all around" So I'm assuming this was a factory installed option for the side window & rear hatch not just the strip in the windshield. Either way, hope it comes off easily with ammonia.

Unless the options sticker in the spare tire well has option code 443, 463, 468, 567 or 568 (463 and 468 both being highly unlikely on a US car), the car never had "factory" tint. It may have had a dealer-applied tint, but that's not factory.

The official Porsche text for those options is never "window tint all around" either, which makes me think that you have a dealer-applied "option". Note also that none of the factory options include a tinted rear window.

443 Tinted front and side glass, heated windshield
463 Lateral glasses tinted, (version for Australia)
468 Graduated tint windshield, green side glass
567 Windshield green graduated tint
568 Tinted windshield and side glass

Well the ammonia trick didn't work. I don't think it ever got hot enough. I ended up using a heat gun, razor blades, goo-gone and some burn cream for close encounters of the heat gun. Cleaned up nice.