speaking of which... you may want to go during the day time... avoid weekends like the plague - unless you feel like not leaving til 2-3am since ppl are continuously going up and down certain roads and you have to wait for it to clear before coming back down... also, cops know about all the popular ones - good thing (or not) that you have an FX, which is much less likely a car that is seen in the canyons and that will be profiled as "racing". Pack a couple bags for camping gear and such in the back as your alibi. .
But yea, try autox first - there is one coming December 10 - lots of nissans (240's in particular) will be rolling out for this one - check
http://www.solo2.com. Hope to see you there - at the track that is, it would be really nice to see how well an FX driver would do in person.