I used 3M adhesive remover to get old tint adhesive off the windows. To remove old tint, simply start at one corner and slowly peel back.
I am a big believer in tint-Dean, point well made but I guess I'm a little selfish and prefer NOT to burn my @#s every time I get in the car. To compensate for my decreased visibility to others, I obey all road signs & signal before I EVER change lanes
As to tint, the somewhat reflective, lightly tinted 3M product is how I went on my white '88 300TE. Looks and works fabulously, but does suffer from decreased radar detector sensitivity to the rear (metal tint). Surprisingly, it looks fairly OE because it's not overly reflective.
My 500E is tinted with a non-metallic, less reflective tint, and I think from a cooling standpoint works only half as well as the metallic stuff. And doesn't look nearly as good in my opinion, but does look fairly OE.