Okay. What is a good in Dash Nav with USB for 450 or under... Do all in dash gps's fit double din?

 

Frankly there is NO good in-dash nav at that price. Even the in-dash nav systems in the flagship headunits (Pioneer Z130bt, Kenwood DD9980) don't come anywhere near the quality of the Garmin sub-$200 standalone units, which often feature lifetime map upgrades and traffic for free.

Get one of those and a solid non-nav unit (Kenwood ddx series are nice) and you'll be a lot better off.