Just checking to make sure the 2nd Gen Red/Black interior (Only the seats and door panels) will fit the 1st Gen cars. Will i encounter any problems fitting the seats or panels?

 

I am not sure what you are referring to in terms of first and second gen.

However, the seat design has not changed for the life of the car. The color choices have evolved, but the seats are the same so any will fit any year.

The door panels in '02-'03 have tweeter pods, and in '04+ have tweeter grills and a little bit of a dip in the door panel offering a little more shoulder room.

If you take a door panel from an '00-'01 and fit it to a newer car, you'd have to address the tweeter. Other than that they should be interchangeable from any year to any year (again, the speaker notwithstanding.)