http://m.aliexpress.com/item/32581650373.html

This little fiend exists on Aliexpress. It is a few dollars/pounds, and I can't see any reason why it shouldn't work with a Pi.

I always thought CAN bus communication would be expensive, but if I can get this to work, then it's game on!

Ideally I would like a Beastie that interfaces to the pi via i2c or serial as they are methods that I use most, but beggars can't be choosers at this price!