My point of view:
Jaguar is better, although has a bit worse graphics. You can easily identify each car on the track and even its driver (each has his own abilities and skills and so if you see Porsche 959 in lead, you know it must be Dyson etc). Also there is the fuelling and you have to repair your vehicle/s and save money for world travelling, which means you must manage your world tour depending on funds. I also appreciate mouse controls. And beside this, Jaguar has brutal engine sound.
Lotus has better graphics, looks more smooth, but has anonymous and totally dumb computer drivers and no any additional value for me. But it can be played on two Amigas and it is a good party game then. I will always prefer Jag though.