My 1986 ae86

[Ivan141]

I see some familiar sights there, and some odd ones too.

The floor rust is not typical.. you really should inspect it further by removing the undercoating around the rust. If it rusts towards the sill you might be in for a bigger job than it looks. Just the floor is an easy fix.
The bit near the rear wheel floor is also one I've never seen before. Looks like it's right above the chassis crossbeam that the panhard support sits on. Interested to know how this spot got rusty in the first place.

The spot behind the rear seat is a very typical disaster area on zenki ae86's/
Thank Toyota and their 4/5 layers of sheet metal in a vulnerable area.
Look at my project thread to get an idea of what things will look like underneath (the holes where patched up on mine but if you look at the welded bit's you get the picture).

Rust underneath the roof is an odd one too.. Only other car I've ever seen it on is our Trueno here.. it's standing-still on the street for extended periods of time that does this too hachi's I reckon. The roof is currently off the trueno to fix that...you could try keeping it at bay with some acid & rustconverter for the time being though.