Originally Posted by craz azn
To race in BMW CCA Club Racing, check this out. Rules are plentiful though http://bmwccaclubracing.com/
To race in CASC regionals, its more like bracket racing, based on times than anything. http://www.casc.on.ca/
To build a car to try and garner the most exposure you can, check this series. An up-and-coming series, probably as close as amateurs can get to a pro feeling gig nationally. http://www.touringcar.ca/
BMW Club racing has too many rules and it's not real racing. The 13/13 rule is supposed to keep racing clean and accident free to avoid costly repairs... but traveling to different tracks all over NA, to have any chance in the championship, costs way more than an occasional body part IMO.
CASC has huge fields, great variety of cars and no rules on car mods. You just have to make sure that your car is competitive at the top of a chosen class. Come out, watch a few races, you'll get the idea.
For Touringcar you will need a fairly new car, entry fees are higher than the others mentioned and it only has two classes.
What car do you plan to race?