i went to rotate mai tires today and i couldnt because of a little pin sort of thing on the inside of rear rim. the pin goes into a hole in the rear rotor but theres no hole in the front rotors. i was wondering if every one was like this. or if it was something the previous owner did? thanks

The rear rims are wider than the front rims.
You are suppose to rotate mr2 tire from side-to-side.
If you have directional tires, this will require you to dismount them and remount them.