For me, the center in steamvr changes position every now and then (the viewing angle), but in most games you can use a recenter button. Project Cars has a recenter button I think. I haven’t ever had the problem that I have seen with the HDK2 for instance, where your head drifts sideways. It’s always firmly on your body.
The Pimax’s rotational tracking is excellent. I have never had a problem with it except for occasional recentering.
I only have Radial G, so can only talk about that, but in my experience the Pimax is great for simulation games. I could play Radial G all night, if the game itself wasn’t tiring. I haven’t had comfort issues, can regularly play for 2 hours at a time.
The biggest problem with Pimax is the ghosting, but in simulation, cockpit games, racing games, it’s barely noticeable because you aren’t moving your body around so much. I haven’t tried the Rift, but for driving games I imagine the image quality and relatively low (it does exist) SDE is more important than positional tracking.
So basically yeah, I’d say for driving games it’ll be fine.