05 NAV system installed in 05

[89vette]

I have been reading of installing the 04 and 05 NAV units in older vehicles. I have an 05 with the 6 disk changer and XM. If I buy an 05 style NAV, do I need a separate antenna for the GPS or does it work off the XM antenna?

Thanks

[89vette]

I have been reading of installing the 04 and 05 NAV units in older vehicles. I have an 05 with the 6 disk changer and XM. If I buy an 05 style NAV, do I need a separate antenna for the GPS or does it work off the XM antenna?

Thanks

[89vette]

I have been reading of installing the 04 and 05 NAV units in older vehicles. I have an 05 with the 6 disk changer and XM. If I buy an 05 style NAV, do I need a separate antenna for the GPS or does it work off the XM antenna?

Thanks

[LasVegas]

Did you mean "03 with 6 disk changer and XM"? GPS doesn't play off the XM. It needs its own antenna located under the dash usually.

[89vette]

No I have an 05 with the 6 disk. I thought maybe teh XM and GPS shared the same antenna.