Forgiv me but i'm new with this car:

i've seen a few comments here on s4's & s5's. what are they? I'm thinking model configuations, maybe something to do with turbos? I've got a 90 n/a convertible... or should i say "vert" since i've at least picked up on that... Does one of these apply to me?

any other configuration things i should know to educate me would be good too.

thanks in advance for the info...

 

S4 86-88, S5 89-92



Look at FAQ, its all there.