I've heard of those products as well... but I'm not gonna claim I'm some great car mechanic or body shop worker... I know how these things are supposed to be used... but, uhm... I don't exactly wanna learn how on my bimmer. :P (ya, I'm too chicken to try)
That's why I was asking on Ziebart's "classic car" treatment, and if anyone here has ever tried it. They apply some rust converter as well, prior to painting. I guess if no one has tried them, I'll give them a try..it's a small spot anyway, in an unseen part of the car (behind the trunk carpet, sidewall) ... Inspection II didn't show any sign of it...and I wouldn't even have seen it, had I not tried to access the amp of my stereo, and check on the jack.