Old thread, but that is a facelift car, unusual to find one on a J plate. You can tell it is a facelift by the mirrors, assuming they are original, though I thought all facelifts had a drivers airbag, so could be wrong. In all probability it has had the Recaro's swapped with a 1.8i XR2i.
IIRC RS1800's were pretty slow sellers. We had one with Recaro's on a K plate, but that was an early RS1800 that sat around for a long time before being registered.
I thought the only RS1800's with wing backs should have a swirly material, rather than the Fiesta Turbo velour fitted to early ones and 1.8 XR2's