That sounds like a pretty big ask from any kind of camera, assuming you're hoping to track the car through a pan with the camera keeping track of the car?
I've had success shooting full size motor sport using the E-PL5 and E-M10 (i and ii) but I don't try and use CAF. I use single AF and if I can be bothered to weed through them - the sequential low setting so it acquires focus on each frame of the burst. I'm only shooting for my own amusement so if I get a blurred image there's no harm done.
Having seen RC track cars at Crystal Palace years ago I imagine they're a much bigger challenge, unless you're happy to fix focus, shoot bursts and throw away all the stuff out of focus.
If you wanted to try the E-M1ii and you live near a participating dealer the Olympus Test and Wow will give you a free 24hr test drive
https://wow.olympus.eu/
It's still a chunk of money, there's no getting past that!