Hi Riks,
I've just come back from PSJ about a week or so back.
I did see guys go up to Poenskop by car, I can tell you I wouldn't even attempt it, the road is bad, there is a river/lagoon you will have to cross, if your car is low, you'll be in trouble. I would strongly recommend a 4x4.
The road up to Poenskop after the river is scary as hell, almost a 45 degree incline at some places.
The bay to the far right of Poenskop is a good place to fish, but will require some walking. The bay to the left, near the beach is also good, very deep water or just off the front of the rocks is also deep.
Get there early, like pre-dawn and try for live bait in the bay to the left. Pinkies, shad or karro's are good bait. Or try an ocky leg for Kob if you go at night.
Hope that helps...