This is a pretty fun group game, but can drag a bit with multiple players. This is because people want to calculate their moves on the board before committing to the best possible route.  A fun variation we like to play is that when you start your turn, you declare your gear and then roll.  Once you roll, you 'drive' the car the necessary moves.  No take backs, no do overs.  This encourages players to pay attention to their car when it is not their turn, and also adds and element of hazard that would be present in a real driving\racing situation.  Makes a good party game, but you may want to limit games to one lap per game.