London to Plymouth - know any good route?

... i'm going to go back and have a double look for other people's route and try and match it (mix of A-road and country road).

Mebe give any route the once over with Google Street View? It's great for checking out new places that you're not sure of.

Also, for starters, avoid the A30 coming out East of Exeter. It's a dual carriageway (check it out using the above method).