I don't know. Good question. You will have a unique player id, i.e. your
name, but the cdkey could be assigned to another. Two bad possiblities,
1. The former owner was a wrecker and got banned by Papyrus, this means
you won't be able to run on Sierra Servers at all. However, there are
private pay-to-race online companies like OLR that would be able to bypass
this problem.
2. The next possiblity would be the previous owner is using a virtual CDROM
scheme to bypass the cd copy protection. If he was online BEFORE you, then
you would get an error message that the cdkey was in use.
3. Third possiblity is the guy didn't race online and you would be clean as
a whistle.
Thunder my someday bypass Papyrus, but right now, online with nr2k3 is
way ahead.