[Eddy K]

Most NHRA tracks are going to require that you have a roll bar that meets specs. You best bet without making modifications is to find an IHRA track or a small independent track. Most of the independents will let you run just about anything.
At our local track, tech is a joke. No one trained or anything. Just go sign the form and go racing.
It is always best to follow the saftey rules as they are there for your protection. However, I am not going to alter my car to put a rollcage in it and as you say, you are safer in a Cobra than on a motorcycle.
The choice is yours.