I just got mine back from the paint shop. One thing to be careful of is that the mustang has water collection areas that create rust. The lower lips on the fenders and quarter panels, the drip rail and most important, the windshield and rear window frames, under the trim. I removed the glass, and found rust, even though it did not show with the weather stripping still attached. I highly recommend removing the glass.. If you are going to remove everything else, why not. Pay the $35+- tow bill and have it towed as a body only. You already said you removed the interior. This is a perfect time. Take a look at my gallery to see the progress.
