Gaah, DSP hookup used to be perfect back before the graphics worked
yeah I see that now. I went back a few versions...and between release versions 122 and 123 something broke with the driving gameplay (DSP?). Something between Dec 30, '07 and Feb 9, '08.
.122 and before has fine gameplay but bad graphics..It is quite entertaining to use the rear view mirror (which has always shown the ground graphics) to get around the track.
There was what appears a significant re-write in SVN1479 but I didn't get a chance tonight to go figure out if it was that specific change (MAME122u3 I think) that caused the break. I didn't see anything else significant in the mess tree. I can do that tomorrow night if someone doesn't figure it out or speak up. Cheers!