I interpret this as the front axel and wheels on both sides of the car must be directly across one another...this would mean having 3 wheels on one side of the car and 1 on the other is illegal....it also suggests that you cant have two wheels on one side at the back of the car and two wheels on the other side at the front of the car so agree, no staggering.....so yes to your description of the rectangular shape....but I guess it could also be square if you want a short wheelbase! And obviously no replacing NDFW wheel with a guidepin.
If this is different from what others interpret please post!
the 45 degree thing just allows you to take one wheel and intall it such that it angles up off the track but if you look fron the front of the car, the angle is not more than 45 degrees from the standard position. Otherwise one could just glue it flat on top the car LOL....Now whether or not there is more speed with this position than just the standard postion is up for debate!
WK