We've been passholders for a decade or more now, back when they *first* gave you a nice laminated pass (like a credit card) but with no vehicle-tagging required. Some years we camped more than enough to make up for our dual passes (one for each car), some years like the past 2 we haven't been as fortunate about getting out and enjoying our parklands. Either way, we look on the passes as money well spent to support our parklands.
More info on the Texas State Parks Pass ->
TPWD: Texas State Parks Pass
I also have the
TPWD "Keep Texas Wild" horned lizard plates on our Ford Escape Hybrid. The plates cost a little more to renew annually but that money goes to fund
TPWD's wildlife conservation efforts (and, of course, a small portion goes to administration fees of the program.)
More info on the
TPWD-related Texas license plates ->
Conservation License Plate
You can even see what particular projects your particular plate is helping to fund (nice new feature of their redesigned website; that wasn't there when I ordered our plates! ->
Funded Projects: Conservation License Plate)