I'm using one of these, for £80 its great value for money:
http://www.carcamera.../mini-0805.html
(edit still available on eBay for cheaper now, £65!)
http://www.ebay.co.u...m-/171397354236
Review here: http://dashboardcamerareviews.com/mini-0805/
The supplied cable is long enough to route down the A piller, along the door trim and into the AUX socket behind the drivers seat. Its fit and forget, comes on with the car ignition and switches off with it too. The hardest part about the whole thing was buying a Class6 microSD from Amazon to put in the thing
If you would like any pics or footage from the 350z let me know and I'll go into the garage and get some for you.