UKH

Some friends and I are heading to Snowdonia this weekend for a hike and wild camp.
 

Are there any issues leaving a car in one of the road side car parks overnight? I don't want my car being there overnight to cause any concern for "lost" walkers and prompt a response from any emergency services but I also don't wish to draw attention to the fact that we're in there camping "illegally" by leaving a note in my windscreen.

What's my best move?

Cheers

Do you really think anybody will even notice that the car has been parked overnight?  If you're worried, why not leave a note on the dash with a phone number they can call - your spouse, parent or the prison governor.

That's basically the question. I don't know how the emergency services operate in Snowdonia. If an empty car in a car park only used by people walking in the hills won't raise any concerns after dark then there's no problem

The laybys around Snowdonia are always littered with cars and "stealth" camper vans of a weekend, even overnight. No such thing as an empty car park. I have never seen any emergency service vehicle patrolling the main roads in Snowdonia after about 8pm - only ever with blue lights on at that time. You'll be fine.

Beautiful. Thanks for the info.

Cheers

I'd be more worried about it getting broken into than raising false alarms. Not saying its likely but it does happen.

Definitely possible. Leave your car visibly empty of all expensive outdoor gear and you should be fine. 

Theft from parked cars in popular outdoor areas is common.

If you write 'Batty Milk' on your car people may leave it well alone. 

As others have said, it's a bigger risk that your car will be broken in to. If possible, leave it in a P&D carpark like the one next to the YHAs in Ogwen or Pen-y-Pass as they always have a few vehicles in and plenty of people around. If you stick it in a lay-by then you roll the dice.