PS2 Driving Games - what to get?

[TransAm]

I have $100 on a gift card for one of the game/movie stores after trading a load of DVDs in last weekend

I would like to buy a couple of driving games for PS2 on the way home tonight, I am going to get TOCA2, but for my other choice I am undecided

I already have GT4.

Is there anything else worth getting, or anything that will be released in the coming months that is looking good? I have read about this 'Enthusia' game...