My 2009 BMW 335i is too expensive to repair I'm trading for another car so I'm thinking to get 2012 Cadillac CTS with 70,000 miles for $15,000 from dealer. What's your thoughts on this car? Would it be cheaper to maintain compared to BMW?
Pass on it. You would be going from the fire into the frying pan.
If you're serious about getting something cheap to maintain, you need to give up the flash and purchase a reasonable, practical car. Odd coming from me, I know, but sports cars and luxury cars (or sports sedans, anything German, Cadillac, etc.) will ALL be expensive to maintain. It is the nature of the game.
It is up to you to decide if you want to keep shelling out money on those types of cars because they are worth it to you, or if you'd rather save money and step into something less bling, less fun to drive, but more reliable and cheaper to maintain.
Avoid at all costs unless you like spending time and money on repairing a car.
If you want a luxury-type vehicle Lexus would be the go-to brand. Of course before buying do your research into specific models that have problems and have a mechanic check out any you are considering.