Gps Antenna

[88K5]

Question about gps antenna. I'm looking at installing a nav/dvd/touchscreen unit in my 2010 sierra. I have the bose system with the on*. It has nav thru the radio that is in the truck now. Does this meen it has an antenna or is that going thru onstar?

If I need to purchase an antenna what part number do I need to look for? Is the USB the only difference between the 09-10 head units and the 08-older units?

[C. Charles Hahn]

First, only the 2010 headunits have USB available. Second, the NAV system does use a separate GPS antenna, which is available here:

 

http://cgi.ebay.com/2007-2010-GM-GMC-CHEVY...=item45f2b45127

[88K5]

Thanks. That's what I was looking for.