Nice "T500 RS Wheel Plate" available here:
http://simracinghardware.com/wheel-plates/thrustmaster-t500-f1
T500RS Wheel Plate
SR Hardware's Thrustmaster T500 SLI Mounting System is a unique concept that finally allows T500 wheel owners to enjoy the benefits of an 'on wheel' shift light system yet still retain the original wheel and fit without drilling or modifying the standard wheel.
Built using our multi-layer construction technology from the finest materials and high quality components, this mounting system breaks new ground in add on hardware for the Thrustmaster T500 wheel! Completely pre built and assembled, the user has simply to attach the SLI-Pro or SLI-M on to the mount with the included fixings.
The mount comes complete with four modified Rotary encoders / knobs again pre fitted and ready to wire to your SLI unit, or you can simply order a fully assembled unit complete with the SLI-Pro or SLI-M installed and wired!
Fitting the unit to the T500 wheel is very straight forward. We utilise a high tech 'Adhesive gel gasket' on the bottom of the unit, whilst a see through acrylic plate mounts the top of the unit using the original screw hole for the wheel band behind the top of the wheel rim, making for a very secure fitment.
<a href="http://www.youtube.com/watch?v=Sm_QLWNUzs4">YouTube Link</a>