Thanks. I wasn't aware that Final Lap lacks roadside sprites only in attract mode. In game they are visible (with the usual position glitches at full zoom).
And I am happy to see that with Yamaha PSR-60/70 the first traditional tablehooters (not professional synths) found there way into emulation. I own a Yamaha PCR-800, which is a PSR-60 variant with PlayCard system (plays a sort of midi files from magnetic tape scoresheets, including keylighting). I haven't dumped the roms yet, but it may be very similar.
Yamaha PCR-800 Keyboard 16 Sounds & Features
There was also an oriental keyboard variant named PSR-62 with additional buttons for arabic scale. (I don't own this.) Both may be similar enough to be emulated.