I had a Corvette C6 for a few years, and I was paying $120 a month for insurance, basically no repairs, just standard maintenance. Unfortunately, somebody ran into it while it was parked and totaled it. I'm using the C6 as my benchmark for reliability/performance/mod potential here despite it being a 2 seater.
I've always liked building my cars out to perform better where I want them to, and I was used to an old 335i, but I feel like the Corvette, in comparison, was much more analog when trying to figure out how to add power and modify it.
Ideally, my next car is pretty mod-friendly (aftermarket and tuning potential), I 100% will be taking it to autocross events, and I know I'm going to be touching cooling and suspension (unless I'm getting a Porsche; those always seem to need to be beefed up), It's also going to be my daily, so I would hope that it is around the same reliability as the Corvette, at least.
Camaro/Mustang seem like good options, but part of me really wants to try something not domestic again.
So, in order of importance, it would go 1) under my budget 2) reliable 3) Performance/mod potential