I know what you mean, we came back through Plymouth 2 weeks ago and luckily were put in the left hand lane, the whole experience of going out and coming back via Plymouth has put us off the place, admittedly it was pouring with rain when we left but the route through the city centre is not particularly well signposted, and dodging bus lanes etc with the van on the back was challenging. We only chose Plymouth/Roscoff because it left us closer to our site once we got to France, will use Portsmouth which is nearer to us in England next time, St Malo out and Caen back, all easier to navigate than Plymouth.