new PlayerOwnedVehicles[MAX_PLAYERS][MAX_PLAYER_OWNED_VEHICLES +1][PlayerCarData];
#define MAX_PLAYER_OWNED_VEHICLES 4
Merry Christmas!
If the define is under the PlayerOwnedVehicles variable, then is that maybe the problem..
Set your define MAX_PLAYER_OWNED_VEHICLES above the PlayerOwnedVehicles variable.