Points of significance.

1.Catalyst
2.Euro spec manifold
3.Better carpeting (?) - Gold Port p72-73
4.Bumper = even bigger (overall length up by 7.7in!)
5.nb. Goodyear G800 Grand Prix tyres. Nb. Looks like rear 'seat' is now carpeted platform (Gold Port p75)
6.Options: Leather upholstery
7.Metallic paint
8.AM/FM stereo radio/cassette
9.Hardtop
10.Alfa Romeo US Spider 2000 1978
11.Outfit as Spider 2000 (1978)
12.Air con option (knob and ducts in dashboard)
13.Alloy wheels standard
14.New exterior/interior colours (+ tan or black hood)