Mega-Tech is a Megadrive/Genesis unit in an arcade machine, hence the game is the same as the Megadrive/Genesis version but currently isn't fully emulated (broken road layer last time I tried it).

The arcade versions are different revisions. The default "smgp" ROM is the most recent, however most of the more recent ones have the fake almost-real advertising hoardings changed and the McLaren on the start-up screens has its Marlboro logo/colour removed. If you check the other variants some have these original graphics still in place (basically Sega got in trouble and released updates to remove the almost-real content).