I was going to mention Ardent Raceway as i noticed the ramp access rostrum yesterday, a great facility if you like indoor carpet racing.
I run a club for 1/8th nitro and 1/10th electric offroad and was approached by a couple of guys last year needing wheelchair facilities to come and race, as a club we just could not afford to improve the outdoor venue safely so approached local council and Lottery funding for help, were turned down flat for any funding to help improve access
We are building a second rostrum for another integrated track so are trying to design in a raised platform which has ramped access and is high enough to give good visibility.
if i see any other clubs that cater for wheelchair users then i'll let you know