Production for the 89 model RS was 11/88====89


production 88 model RS ;; 11/87=== 88

2 door was only available in the RS in 89 after 89 production for 90-91 only 4 doors were available

88 production had an s model 2 door lwb only

87 models had 2 and 4 doors both LWB
hope this helps if you look at the production date on any of the vehicles and it was made after 10 or 11 month of the year, it is allmost always the next model year
that is the reason some folks think they have an 87 with the 1`2 bolt rear and the fuel inj 2.6 , never happened, all 87,s were carbed , they were getting to the point thewy would not meet federal emmisssion specs , so 2.6 and efi .on the 88