I forgot to come back and post impressions of the early access.
There are two cars available and they are both RWD. One is in a classic American muscle car, and the other in the style of an older European hatchback. They both look good, sound good and crumple with the best.
The driving is classic Bugbear drifting heavy cars, and you can tune it a bit to remove Traction Control, Spin Control and ABS. There are none of the promised garage elements with upgrading parts, repairing, progression or any of that available yet.
There are two tracks (one gravel, one tarmac) and one derby stadium available. You can play either of the races with 24, 12 or 2 cars, and the derby with 12 or 24. The tracks are pretty sparse still and clearly missing a lot of destructible decoration and buildings, but they look decent.
One thing that FlatOut fans will notice missing is the boost bar. This is a more serious game so that arcade aspect of smashing into things to build up boost is gone.
TLDR: it's definitely early days but fans are sure to have fun [for a little bit]. I can't wait to see this fully fleshed out!