are devs working on it?

Not until we have karts, which won't be until chassis flex is modelled, which won't be until S2 is finished at the EARLIEST.

There is (or at least used to be) a small kart track next to the drag strip or something, but it was zero grip land, and thus useless.

If you look through the autocross layouts subforum, you'll see somebody handily copied it over onto proper tarmac.