Yes, probably DEFAULT.TRK, VANCOUVR.TRK and DEFAULT.RPL deserve their own articles. I have already told this, but the version of Stunts I first met was Brøderbund 1.0. It clearly had gone through other hands before so what I will say about it not necessarily describes features of the original 1.0 version, yet some items might. It was March or April 1993 and in Argentina, original software did not exist. Piracy was the only way of obtaining any software. A friend at school, upon knowing that I had a new PC (a 386 DX), offered to come to my place and bring some games. He came with a box of boxes of floppies. One of the games he copied to me was Stunts.
At that time, there were shops in Buenos Aires that were dedicated to somehow obtaining original games, then rebrand them by adding an extra init screen and/or a crack and sometimes a routine that would ask you to enter a password and the password was the shop name. Then, they would redistribute the game by selling cheap copies. In other parts of the country, such us where I live, there were other shops that would feed themselves from these Buenos Aires shops. A guy would visit these shops in Buenos Aires from time to time and buy as many copies as they could, bring them back to Córdoba and then resell. The most famous game reseller (pirate, of course) in my town was called "Wolrd Soft".
Anyway, my copy of Stunts had an extra intro screen that displayed the name of the Buenos Aires shop. Then, a crack would run and the game would kick in. The DEFAULT.TRK was the one we all know, except that it had been modified and one of the paths was incomplete. It seems that version 1.0 allowed for incomplete paths as long as at least one could be driven. Version 1.1 won't let you race if there are incomplete paths (-=To be verified=-). The DEFAULT.RPL was raced on the original DEFAULT.TRK or perhaps on this modified DEFAULT.TRK. I still have the copy, so I'll check. But it was clear that this wasn't the truly original DEFAULT.RPL because it ended in a crash at the loop (the car would shoot up into the sky and then fall and crash into the ground). No VANCOUVR.TRK. A file was missing which caused selecting Skid Vicious to crash when trying to race, but I later found the missing file somewhere else and incorporated it to my copy. The AdLib/SB driver produced strange artifacts, but I later solved this problem by replacing it with the driver from the game Fight (a.k.a. 4D Sport Boxing). So my old copy isn't exactly as it originally came. The crack was a file called STUNT.COM (only one "stunt") and there was a file called MLOOK.BAT that would first call SETUP, then STUNT. STUNT would call STUNTS and STUNTS would call LOAD. If you ran STUNTS, it'd have the "security system" activated.