Hmmm, that's the first I've ever heard that, I'd like to see more info on that before I'd agree. Of the cars I've owned (or parted out) that weren't undercoated, none of them had any primer on the gas tank. If they had, I would've noticed it, especially on a non-red car (red oxide on a gold car, for example). That would also mean that these cars were primed after assembly, but I believe they were dipped for the primer stages, prior to assembly. Keep in mind that we know this particular car was repainted, and seller says it was thorough, so I believe what we are seeing is overspray due to car being painted with rear bumper removed. (just my opinion)