Right now, there is no dealer-installed OEM upgrade from a non-Nav system up to the NAV system. Your only choice is to go aftermarket install (even if you use the OEM NAV unit, which won't give you the energy monitor)

CAMRHEE Hybrid - FOR SALE!!!!
Completed Mods: RK-Sport body kit, 18" LexusGS430 wheels 235/50ZR18 tires, TRD/SE springs, Rear Lip Spoiler, Terk XM-Direct, Smoked tail lights, Sliding Armrest, Rear Bumper Applique, Front License Bracket, Lower Grill chrome inserts, K&N, Blaupunkt THB200A sub, moved rear HSD emblem
Future Mods: fog lights, black chrome my wheels

http://www.greenhybrid.com/share/fil...fterFront4.JPG