Just for the books.
Here in Holland, we didn't have the RS1800, but the same fiesta was badged as XR2i 16v over here (with the 130BHP engine)
The 105BHP 1.8 16v was in a fiesta, but only badged as "S", and was pretty bare ("XR2i 8v seats, no side skirts/wheel arch extentions) standard (but painted) mirrors and bumpers .. and rectangle fogs underneath.

Enginewise, nothing wrong with the 1.8 16v (either 105 or 130BHP) but lacked the torque the FRST has.... but better for daily driving.

I'm pretty sure the additional power steering etc was a huge inprovement, but not much was improved compared to the 2i 8v and the FRST.

The later spec ones (mk3.5) had a fuel-cap-door in stead of a fuel cap, but rusted as hard as the mk3 ones, but this was covered by the fuel-cap-door

There are some more design flaws in the mk3, which they haven't solved in the mk3.5.. all related to rust... just to name a few:

- water disposal holes of the bulkhead .. dripped water ONTO a weld .. which was welded inside out (the lower plate was on top of the upper plate .. it was sealed off, but still water and dirt remained on the seal.. causing it to stay wet all the times, creating a hole inside the wheelarch @ hight of the side repeater.

- seat mounting points .. they stick out, catch dirt, stays wet.. rusts...
- wheel arches.. no comment
- Battery tray, and the beam below.. always trouble..
- around front windshield.. They placed some tape on the corners.. in stead of paying some attention on closing off the welds
- door-rubber ... is open to water, tends to rust .. drips on the not very well welded panels.. which start to rust too.

But in all.. the RS1800's . or XR2i 16v's as they were sold like here (without the recaro's )-: ) are pretty nifty cars.. and great runabouts (-: