Ok this search has just gone off on a tangent. City bomber is indeed the start of the game I was asking for help in identifying - I'm amazed to see it after all these years.
The problem I have is the 12 DOHC thing. I definitely recall a stage where you finished the race and either round 2 or 3 race was in darkness and you could only see the track / path with your car headlights.
It's obviously a different game and my somewhat flaky memory has merged two games in to one
Anyone have any ideas ?
Thanks for your help so far - seeing city bomber has made my day. I'll be playing that as soon as I sort some free time.