I hope Scawen added code to blow the engine after a couple of laps, wouldn't be real enough without a huge cloud and oil on the track... it's a BMW :-)
Nah, it would absolutely murder the poly count. If you imagine that the top surface of the tyre is maybe 3 polys 'wide' at the moment (to allow for a bit of bulge) to make a 4 grooved tyre, you need at least 17 polys for each radial segment.