I got a shallow scratch from some automatic car wash and have been cleaning my ST at home ever since. Still have to fix the scratch though lol
Mine has never seen one of those paint/clear coat killers, and as long as I own it, it NEVER will. (It has only seen ONE even hand wash not done by myself, and that was for a sealant done at a detailer when it was a couple of days from pickup at the dealers when new.
)
But yeah, I understand, especially where you are located, in the heart of the 'salt soup bowl' conceding to one of those evil monsters to get that crap off of your car when it is -10*F out, and there is NO WAY to do this yourself.