will 88-89 seats fit into a 90-91 civic?

 

Not directly, the rails are different. You can swap the pans though.

 

do the seat pans bolt out? sorry for the noob question but is the pan attached to the seat or the floor of the car?

 

the rails are attached to the frame.
the seat pan is attached to the seat rails.
the seat foam is attached to the sear pan.

make sense? the rails are bolted to the frame, which can easily be removed.
the seat pan is bolted to the rails, which also can be easily removed. the foam however is clipped on to the seat pans [which looks like a bent staple] which is also easily removed with a pair of dikes or pliers.


so take your seat pan AND rails from a 90-91 civic and switch it with your 88-89 seat pan AND rails.

 

^ He's correct. To summarize, you'll have 88/89 seats (the foam) in the 90/91 rails/pan. I'm planning on doing this myself, actually. Although I'll probably be swapping a 90/91 passenger to my 90/91 driver side.