Wikipedia can help you identify the pre-facelift and facelifted E46 3-series...check out their Gallery. The facelifted 318is have the Valvetronic 16-valve 2.0L engine.
http://en.wikipedia.org/wiki/BMW_E46

This is how a UK RHD unit looked like, but aside from the steering wheel it's pretty much identical mechanically to ours. Note the headlight housings.
http://en.wikipedia.org/wiki/Image:Bmw3black.jpg