i'm more into the performance side of kit cars, and as such i see a few possibilities:
1 - v8 musclecar to cater for those who currently go for cobras or TVRs, front engine RWD
2 - supercar for those contemplating Ultima, Lambos, or even McLaren F1, mid engine v10 or v12 (perhaps v8, but they're not my thing)
3 - Ferrari F355
(just joking)
4 - mid-engined v6
track-day and road car, probably soft-top and fixed top versions
5 - front engine RWD small beastie for track and road, single chassis with options for a 7 or MX5 type bodywork - both totally up to date styling wise of course, probably with 1.6 to 2 litre 4-cyl
i look forward to when you finally get your designs onto the www