Welcome to Vienna! I've been here 30 years now, so I can't say how my living expenses would compare to the US, but I certainly love it.

I'm not sure why you brought that car unless you plan to sell it. At the time I moved, I looked at which cars were selling in Austria for much more than in the US and required minimal changes (turn signal lens colors, etc.). There were other factors that I won't go into here, but I brought my 91 Celica convertible and got it registered within a few months.

Maybe it will be easier to register with such and old car. A key is to make sure you have all your documents lined up before you arrive with the car. Here's a useful link if you don't already know it:

https://www.oesterreich.gv.at/themen/mobilitaet/kfz/13/Seite.061610.html