You may occasionally see an exception to a rule. Sometimes things get overlooked, and sometimes a car is not protested when it is in violation of a rule. Usually this happens when there is no established record, and there is no one to guard and existing record. If you are planning to do something that is borderline, you should determine if what you are doing will benefit you enough that it is worth the chance. You could also mock up what you are planning, take a picture, and send to a rules person, and get a yes or no on the change. If you do this, keep a copy of the correspondence in your records. Do not base you decision on someone's unofficial ruling, an existing car that is running, or someone opinion the ran a car in your class in the past. Keep in mind that just because a car has passed tech, and is presently running on a record in a certain class, it does not mean that the car is legal to hold a record in that class.
I have been involved in more than one interpretation of the rules. It is much easier to work out any possible problems before you show up to run at event. Spending your time at an event trying to make a race car legal is not much fun. However innovation is what land speed racing is all about. Thinking, and take advantage of the loopholes, may result in that little bit of speed that others have not been able to get. You have to balance that fine line, to be legal, and to run fast.
John