Not much more help, but mame and
system16 say the game has an extra "widget board", that handles ethernet and analog to digital conversion. If the shifter is like harddrivn' full size sit down, and uses an analog shifter, I can see something wrong with the board making shifting bad.
However, I know that board handles the pedals and steering, so ... Add that mame has the gear shift as four switches in jamma player 2 buttons 1-4 (though mame might be missing emulating analog shift?, like it's missing the 49-way joystick emulation in blitz/gauntlet games).
...Oh, just found this in mame's notes (
MAWS):
"There are 2 types of California Speed, one of which does not utilise the 4 position shift lever. This was the factory kit that converted "Hyperdrive" to California Speed."
Maybe he has the no manual shift version.
