Does anyone know how to disable the 'Limit Features While Driving' that is enforced on the '08 Denali NAV system. The manual says it may have the ability to disable, but this option is not found under the Menu tab. It is very annoying to have limited Navigation and XM usage while driving. Granted it is a safeguard by 'Big Brother', but if there was some decent engineering at GM they would hook this feature into the passenger airbag on/off system such that a passenger, if present, would have full access to all NAV and XM functions. Currently one must pull over and put the car in park in order to change a navigation setting or scroll the complete list of XM stations...very annoying!