I feel that racing games are represented in a way that doesn't fit my expectations. Please, make a surprise and give us Ignition. Or Big Red Racing. Please!
Also, with EA here, I would LOVE to see them bring in Need for Speed 3: Hot Pursuit. I've only ever played the PSX version, but I spent many, many hours of my childhood running from the cops. That game is absolutely fantastic, and the PC version has mods available as well.
Racing games can be a problem because they often contain licensed cars, tracks, parts, drivers, teams, leagues or other licensed material and it may be difficult for GoG and the publisher to obtain the necessary rights to that content.