It's been said already but back into spots. Since getting my Z other than the first day I owned her I never pull in forwards.
I changed my head unit as well and added a backup camera to help with backing into spots.
My backup camera kenwood CMOS 310 has some really good views including super wide and corner views. The corner views is a bit hard to get use to but it will let you see sideways behind you. I will occasionally flip it on to double check blind spots when driving in heavy traffic on the highway.
http://m.youtube.com/watch?v=zCaf3C5l8Ck