Pressure washers can remove paint as well. If there is the slightest edge for it to get under, it's gone before you can release the trigger.
Tape pinstripe can be removed with several different techniques;
1. Heat gun and solvent
2. 3M pinstripe removal wheel (mounts to a drill)
3. 3M decal removal spray (mainly made for removal of large wood grain decals on old station wagons).
Painted-on pin stripe can be removed via laquer thinner or similar solvent. It will remove the enamel-based stripe paint before attacking the urethane clear coat.
*Note: I would suggest trying a small area in an out of the way area first to check the affect on the paint.