These are what I use.

The spray worked really well on my crown vic ex-police car that had double sided tape all over the place. I used it on the plastic on the mirrors, the vinyl on the dash and on the paint. It didn't leave any stains or mess up the clear but it's a little time consuming. I think I paid around $10 for it at O'Reilly.

The 3M eraser wheel is awesome, you can use it on paint and glass and won't harm the clear. It'll take off pin stripes and bumper sticker adhesive, dealer emblem or window sticker glue comes off with no problem and it works pretty fast. I picked up it up on eBay for $24 shipped.
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