Cheers
Yes, all of the ones I will be playing - rFactor 2, Assetto Corsa, iRacing, Game Stock Car - for a more arcade type experience, a lot of the Codemasters games (Grid iterations and Formula 1) are 3 screen compatible too 
Supermodel Emulator(Daytona USA 2, Scud Race) can do 3 screens as long as your video card accepts it as one big wide resolution.
I don't recall if it was in the last official build or one of the SVN builds since, but it is possible.
Check out the vids on youtube.
There are a few in MAME. Buggy Boy and TX-1 come to mind, although I don't know how well they play without a 360 degree wheel.
IIRC, the extra screens aren't emulated for Hard Drivin/Race Drivin because they required multiple copies of the original pcb running simultaneously. Virtua Racing had a widescreen option. It's not 3 screens, but you'd definitely want to set it to that on your setup.
Edit: Model 2 emulator will also do widescreen on Daytona and Sega Rally if you set a custom resolution in the ini file. (The other games it doesn't work with will just display 4:3). I haven't tried it with ultra-widescreen or multiple screens, but it's worth a try.