When practicing in a season press the number buttons below the F keys up to nine and you can make things around you disappear. It's really cool!
Opponents strength
Under the quick Race menu, just set the opponents strength down to the lowest it will go, which is 80% and then set the damage to no car damage, no yellow flags, no player breakdowns, etc. Have fun, as this applies to both the quick races AND the season races. Hope this solves the problem.
Hex cheat
Go to the Nascar 2 directory ( you might have to go thru Sierra first.) and go to the folder TRACKS, then go to the folder called Taladega, after that go to the file that looks like a read me file but says Taladega, go in it and go to speedway, there will be a number 1 and two other numbers, change the number one to the number 0 and exit. While racing you can reach speeds of 230 mph.