SWMBO and I are planning a trip to California in July. We're going to Laguna Seca for the Moto GP / AMA Superbike meeting. We're also planing on doing a bit of the ol' road trip thing. Last time we were there we did 2K miles in a week in a rented Mercury.
I'd like to obtain a copy of Garmin mapping software for the US so that I can start route planning and ultimately navigate on my SPIII. Does anyone have any ideas how I might achieve this?
Any good advice gratefully received......

I'd like to obtain a copy of Garmin mapping software for the US so that I can start route planning and ultimately navigate on my SPIII. Does anyone have any ideas how I might achieve this?
Any good advice gratefully received......