My advice is DO NOT sand blast the body panels. You can and likely will destroy one or all the panels. And we aren't talking about "Damn I have more work to do" kinda damage, we are talking "#^@& I HAVE TO BUY A NEW HOOD!" kinda damage.
Unlike the common myth that the sand blasting is causing heat to warp the panels (I too thought that for yeas. You are blowing air on the panel so it actually gets cooler, try it, I have, after sand blasting the metal is cooler.
The warpage is caused by "Mechanical compression" that being each of those pieces of sand is like a tiny hammer putting a little dent in the surface of the metal stretching it. The top surface of the metal gets larger than the lower layer and it warps.
Can you sand blast sheetmetal without warping it, yep you can. I don't see a need to see when it works and when it doesn't personally, I am going to find another way like chemical striping or sanding it off with an orbital sander which creates much less heat than a "grinder". But I wouldn't be sand blasting it.