I know this came up before because I was actually looking for help with this. Anyway, I was able to remove the pinstripes on my '01 A4. All you need is rubbing alcohol and your fingernail. About a half hour for each side.

 

http://www.autobodydepot.net/scripts...sid=0515034003
Use one of these! you can buy the rubber wheel at your local auto paint shop for about $10 and use it in a drill. it'll take about 5 min per side & much easier on your finger nails!
also great for removing adhesive residue etc..