<< anyway, i think this is not transferrable. say you went out w/ your friends using 4 cars, only 1 car is eligible for free entrance/parking. >>
Yes, the pass is transferrable. Meaning you can use it and then loan it to someone else for use at a different time.
Of course, you CAN'T use it in multiple cars at the same time! That's like going to Disneyland and buying one pass
for 4 people and expecting the park to let all 4 of you in. Too bad it's only a day pass. I don't go much to the state parks anyway.
On a side note, you can get the Golden Eagle Passport for the National Parks (ie Yosemite, Grand Canyon, Yellowstone, etc.)
If you use the Southern California national forests, it may be worthwhile picking the Golden Eagle Passport. If you buy at Golden
Eagle Passport ($50/year) they will throw in a National Forest Adventure Pass ($30/year value) for free. My coworker calls it
the National Forest Extortion Pass.