not sure if the 2k tyre phisics is 'real' (ie a timer interupt running a 2k) it may be, but even so its the overall physics rate that matters (the one hitting the springs and dampers) ie a vehicle traveling at 300 kph, the 100hz engine will 'sample' every 83 cm but to accuratly sample you need 2.5 times what your sampling so therefore 2m is the minimum 'bump' length.
Im not a phisics person but have worked in the reatime software/hardware industy before, so thats is where im baseing my info from.
BTW i think netkar is 500hz, iracing is also going to be high and wasnt gpl at 273?
This isnt a critasism of the current system (it is what it is) but upping the rate may also allow simulating other things aswell (flex maybe?) i cirtainly wouldnt say upping the rate is a crude way to solve problems, it only brings benifits (with the exception of system performance)
BTW i also agree on the 'backtraking and sanity checking' but in addition to uping the rate
Simon