i don't think a curb is needed...the white side lines and the cone at the exit give all the depth/corner information needed. modify your line to stay on the track
sounds a bit like you want a ghost replay, and there is an unofficial add on for ghost replays, but i've never used it so i'm not sure if it functions exactly as you are describing.
that said, the more laps the AI cars run, the better they get at that track. i've read that some people will start up a practice session, load it full of AI cars, and leave the game running for a few hours. apparently, the AI cars will reach their full potential after ~60 laps on a give track.
also, not sure what version of directx LFS was programmed with, but the gf2 card is a DX7 card. If LFS is using DX8 code, its possible that could be causing the problem. but first, i'd recommend seeing if you have the latest version of directx installed (9c i believe).
looks good, only thing i noticed, is if i was designing this skin, i'd rotate the honda logo on the lower rear wing 180degrees so that it has the same orientation as the Pepsi logo on the upper rear wing. but that's not crucial. just my thought on it
oh, and defrag is a way to optimize the harddrive so that related files are next to each other on the disk, which increases the read speed off of the disk. but since you're problem doesn't happen offline, that's probably not the issue here.
if it does, then it could be something on your machine that's causing the problem. installed any new programs around the time that it started happening? Any program updates? Also, antivirus programs and antispyware programs can cause performance issues in games, so if you have those running, you might want to try disabling those. and if the problem continues, maybe try defragmenting your hard drive.
this happens when you have a poor connection to a given server. its called lag, and its usually measured in milliseconds. on the server selection screen, i believe it is referred to as the servers "ping".
basically, the ping time is the amount of time that it takes a packet of information to travel from one computer to another.
the reason that you get the pause is because while the program is running on your computer, the host server is what is keeping track of the information from all the competitors. so, pause is from the remote client (your) computer waiting to get information from the host server. once it recieves taht info, it updates the information on your computer and typically results in a "jump" in location of all the players.
this poor online game performance could also be from an overloaded server caused by too many connections at once. the more connections at once, the more the load is on the server computer.
my advice is make sure that the only program using your internet connection is LFS. if you multiple computers sharing a connection to the internet, then that basically cuts your connection speed in half (overly simplistic, but gets the point across). also, choose different server. and remember low ping times are better. i personally try and stay on servers that have pings below 250ms.
i thought i'd give this a try with a higher-res brake texture (256x256)...
anyways, here's the file and a test shot (no ingame test, i'm at work so its only the cmx viewer)