I just removed my stock "mustang" stripes and washed her, but there is still a glue residue at one small area that won't come off. What should I use?

 

Goo gone, they sell it at walmart and other type stores.

 

+1 for goo gone.

I used it to get the dealer decal off my trunk, worked like a charm! Be sure and wash the whole car after you do it becaues the residue of the goo gone (kind of like an oil) will catch dust/dirt so you'll have "phantom stripes" where your stripes were if you don't wash the whole thing (or at least the doors anyway)

 

a few other ideas

WD-40
soap and warm water
a solvent like PPG DX330 (wax and silicone remover)

 

I'd also recommend using a clay bar on the area and then a good waxing. I just had my stripes redone and my striper told me to put a coat of wax on before he restripped it. This was because the paint didn't have any protection like the rest of the car which was previously waxed and also for future protection under the stripes.