I wouldnt advise it either, my car was damaged several times when parking along the roadside. Parked on double yellow lines before and got a parking fine, have seen this happening to a lot of parked cars. I dont think they would actually tow you away though unless you were blocking part of the road. Tried parking it in the estate a couple of times and was nearly killed by the residents, the car was even keyed once.
Not worth it, better to just walk to the train station. Unfortunately I didnt feel very comfortable walking on the dark evenings of winter, as the road towards Ongar is very poorly lit in places.
Didnt hear of any plans to build a car park, and to be honest I wouldnt hold my breath.