I've had more cars than I care to think about. When rust begins to bubble, esp on old European cars, it seems to find its way back over and over and over.
Then that leads to a re-do and a re-paint. Honestly, I've got no stomach for that anymore.
I really like my Glass car; It has about 2K miles on a re-paint and we drive it. I'm hoping it will last the rest of my life or someone else's: with no bubbles. I can just keep refining and adding; but not fully rebuilding it.
So, I like Glass Speedsters for that reason; I could have a steel one but I don't want one. I have a steel Chevy; that's good enough.