Ok -- I know I said in the last post that the heat gun was doing a good job removing the stripes, and it is, but I ordered a 3M Stripe Wheel earlier this week from Amazon which showed up tonight. The stripe wheel, which isn't necessarily cheap ($20), is totally the way to remove stripes and adhesive.
The wheel mounts to a drill and seem to be made of some kind of medium-hard rubbery compound. You put the drill in reverse and basically scrub the stripe and glue off.
I spent about five minutes testing it out tonight and was able to remove almost all of the adhesive that the heat gun left on the cars belt line. It takes a bit of time to figure out the right RPM, but once you have that down, the job goes quickly.
I'd a post online from someone advising not to use the wheel on the polyeurethane parts (nose and bumper). There is no mention of this in the instructions that came with the wheel. Figuring I had nothing to lose, I use a very, very slow rotation speed stripe adhesive left over on the front fascia and it came right off without damaging the paint of the fascia.
So - my recommendation is to got get a stripe wheel if you need to remove stripe tape. I did see a less expensive, non-3M brand wheel out there which people seemed to like, and I'll probably need more than one wheel to do the whole car, so I might try that other brand if I get a chance.