Not sure how far you are from Bald Eagle State Forest but they have a bunch of car camping spots scattered throughout the state forest. If you call the headquarters they will send you info and maps.
If that's too far there is also a few car camping spots in the Weiser State Forest. The access road is located a few miles north of Cabelas on route 61, near the town of Port Clinton.
There is info online about state forest car camping, DCNR website.