Don't say 'racing sim' say 'driving simulator'
Tell them about the cruise servers (but don't call them that), tell them you have to learn and obey all of the traffic laws otherwise you lose. Tell them about the driving lessons that teach you proper braking techniques, spin recovery and obstacle avoidance.
Load up the demo and show them the lessons where you have to drive around the cones- do this in the XFG with a simple bland color- don't drive fast as you normally would though, drive in a very controlled manner.
Remind them that one day you will be driving them around, particularly in an icy place like Canada, and this may well save their lives- particularly if they buy you a G25 as well.
Otherwise, yeah get a job. And keep those grades up! You'll regret it later if you don't now when it's easy.