STC class question about interiors.

Reading the rules for STC since it does not say I can remove the interior, I must leave the full interior in the car. And I quote:

SCCA said: Except for modifications authorized below, Street Category cars must be run as specified by the manufacturer with only standard equipment as defined by these Rules. This requirement refers not just to individual parts, but to combinations thereof which would have been ordered together on a specific car. Any other modifications or equipment will place the car in Street Touring®, Street Prepared, Street Modified, Prepared, or Modified Categories as appropriate.

I do see mention of removing the interior in Prepared Category. (17.2 H) If I stripped the interior out of my Eclipse, the minimum class I would have to run would be Prepared. Am I reading this correctly?

I believe that's the case. The Street classes exist for cars that could be usable (by normal people, not us) as a regular car.

Yes you are correct. SP and ST classes both require full interior.

Yes you are correct. The philosophy behind it is that although stripping an interior is free, it is a measurable weight advantage thus making it a 'must-have mod' for a competitive car in a class in which it is permitted. So for any class for which the intent is a 'streetable' car, you can't pull the interior.