How soon are you meaning?
Personally, I never pay any attention to "no overnight parking" signs. Just try to keep a low profile and don't stay in the same place for more than a night
Are you after somehwere purely to get 8hrs kip, or "proper" wild camping
I hope you know how to use google streetview, here's a few links
There's a guy on the scottish vanners forum who runs a campsite just outside Fort William, we had a meet there in november and it is a cracking place
http://www.linnhe-lochside-holidays.co.uk/Prices aren't too bad, maybe be worth a stop atleast one night so you can get scrubbed up (very good showers there!)
http://maps.google.co.uk/maps?hl=en&ie= ... 89,,0,7.24There's a large car park by the shore towards the south end of Fort William. I've heard of folks staying there
http://maps.google.co.uk/maps?hl=en&ie= ... 45,,0,8.36Up past Roybridge, in Glen Roy, there is a gravely car park a few miles up.
It is absolutly DEAD up there, only an estate lodge right at the very far end and thats about it. May get a few tourists coming up during the day?
http://maps.google.co.uk/maps?hl=en&ie= ... 73,,0,4.86Up at the very far end of Glen Nevis there's a car park where you can start a few walks from. Busy during the day but I imagine it's quiet when dark
http://maps.google.co.uk/maps?hl=en&ie= ... 8,,0,-0.32There's also a large car park in Glen Nevis closer to Fort William. I think this is the main starting point for walking the ben so will be busy in the summer during the day. But if you turn up when it's dark, keep a low profile, and leave first thing in the morning I can see you having no problem sleeping here
http://maps.google.co.uk/maps?hl=en&ie= ... 3,,0,-6.06