"I couldn't believe it was some amateur's work "
Topgear2 is a real game, used in factory QC :P It isn't amateur :) Its even my dump from my pirate game i bought at singapore when i was a kid :P Haha, its certainely the best arcade racing game for genesis, like 60 tracks and uber fast action (when you put all to the max)...
I asked to erase it, nobody should never see it again, sorry.
About the utility disc, you must be using megacart.exe utilitydisc building functions, right?
Put all your roms on the utility_disc/disc_content folder, be sure to not exeed 255 files in this folder and no more than 400MB (megacd cannot read data with good accurency over 440MB).
Also get sure to have all your roms in .bin / .32x format :)
Ha, yes, a last thing, when you'll boot your fresh utility disc, just hold Start (not A,B or C), else you wont be able to flash anything.
Then enjoy :) If you have any problem, just tell me.
