I know you've said you don't like to drive in LA traffic, but honestly I'd probably just suck it up and drive. I was in a similar dilemma last time I was in So Cal (about 3 weeks ago) and after investigating every possible option under the sun for 'alternate transportation' to both DLR and USH I decided to just rent a car.
Mine wasn't the driving in LA thing, I grew up in So Cal and the traffic (even at rush hour) doesn't phase me. I just choose a lane, put on my tunes, and sing at the top of my lungs. Mine was more the cost as I rented the car for the whole time I was there. Got a real good deal through AAA.