Keep it if you don't get they money you want, these are very sought after and super cool, if people are chomping at the bit and calling from aus, I'd stick to 6k, it's not as if it's ever going to be a hard sell, personally over 6k in your pocket I would keep,(I don't men to sound rude but if your buying an r35 then your not exactly skint) it's as good as cash sat with a cover should you decide to sell later.

Jay