You can make a player carskin with another number. You could, for instance, make a player car #99 by painting a blank (default) carskin with that number and saving the file as XXX99.mip. Then you would need to make a XXX4.3do file (or modify a default 3do file) that has the 'call' for that XXX99 mip file. This would give you a different player car with the #99 visually ... but the 55Mod would still list the player car as #4.
[G.P.L. can be modded to change the player car number ... but that requires even more work, like making the new player car # files (both mip and 3do) for all car types. Plus, if you race online, you would need to change back to player #4 for that.]
Edited by gliebzeit, Aug 19 2017 - 12:38 PM.