I have been using the TVandNav2Go for about 6 months in my 2008 - I updated with the most recent version software from http://mofv.com/mygig/
It sells for $199 with the multimedia/video cable included (less $$ if you are part of a group buy - they do deals, 20+ units brings it down to $125 if my memory is correct). They have a website and ebay store. I bought some cameras from Amazon on the cheap. I opened the dash side panel on the passenger side and placed it in there, cables were long enough.
It appears to be the same Asian source hardware as the $325 Coastaletch lockpick - I've taken mine apart to examine plus the instructions and user interface is identical. Of course these things are largely firmware on an ASIC and I didn't attempt a flash dump to check if the contents are the same - Coastaletech might be adding something better in firmware - I don't know but I haven't seen anything.
I just know that since I do electronics related work I hate spending money on it.
It was difficult to spend $199 - but $325 from Costaletech was out of the question. There is not much to these units - the cost is not the hardware but the design/software development (including any licensing if they bother with that). I'm not recommending one over the other - I almost NEVER recommend electronics - LOL. If you aren't willing to take a chance on no support - buy one of the more expensive units where the company will service/update the product such as NavTV who has been around a long time.
For me - I'd rather spend the $199 and take my chances instead of $325 (coastaletech) or $353 (NavTV Allgig USB + AV cable) Personally, I would buy Allgig over Coastaletech only because it is updateable - odds are the factory isn't going to do some strange update to disable the Allgig but it is nice that NavTV has the ability to make changes just in case).