Tail Lights
 

Can the tail lights from the later model FCs fit on an 88, i mean can the circle tail lights fit on my 10th AE, which have the flat lights? just curious

Yes. You have to grind a spot a little bit to make them fit, and you have to get the license plate holder to go with it. They are not the same size and won't fit each other. But keep in mind that the round tail lights are very high demand and will cost you a good chunk of money.

Does anyone know if the wire harness from the 89-91 hooks directly up to the 86-88 ones.

I think its the same. I have a 89 TII and my friend took the tails outta his 87 NA and put them in his 91 so that he could keep the round tails....they fit in with minimal fuss. He said that he didn't have a prblem locking the lights in place or anything.