Hi Andy,you can walk all the way from the car park west along the single track road all the way to the river Ancholme,viewing the adjacent farm land and wet pasture to the north and south.You can also walk a partial distance from the car-park to the south along the large land drain(Old Soak drain),and to the north all the way to Bonby Carrs.If you choose the walking to the north option, you can join the road which leads down to the Ancholme at Bonby Carrs,join the river bank and then walk back to Worlaby Carrs in a big square,returning to the car-park.This walk usually takes me a good 5 or 6 hours.
If you spend a good few hours you should see all the specialities such as the wintering Hen Harriers,1 or 2 Marsh Harriers,Barn and Short-eared Owl,Peregrine,Common Buzzard and also possibly Merlin.There are also at least 7 Stonechat on site now and good numbers of Linnets,Goldfinch and Fieldfare.
So in reply to your original question,birding from the car is not the best option really.
Regards
Steve