They've split up now, but the bassist, Furukawa Miki has released two albums and they're both pretty good. She was also in an amazing Uniqlo advert, but it's been taken down from youtube now, which is annoying.
I just got the second cd by Miki Furukawa, Bondage Heart. It's amazing. I heard about her through a friend. I just listened to Super Car White surf style 5, and looks like I will have to get that as well.
My favourite Miki Furukawa song is BBW which stands for Blur Blue Wave
If you like those, I would definitely recommend getting some more Supercar stuff. Their sound really changes over time, from early albums that are more guitar-oriented to the later albums which have a much more electronic sound.
Weirdly, when I went over to Japan with my girlfriend, almost none of her friends had heard of Supercar, but then we went for dinner (in an amazing yakiniku place in Ebisu called Champion, I think) with one of her friends, who, it turns out, was the producer on Miki Furukawa's solo stuff.