We've got six vans on the road, all signwritten, and we get calls all the time where people say..."I saw your van...."
All the vans are different types/models, so people know it's not just the same one they've seen several times. They all have the same logo - "Ian Lancaster - Window Cleaner*" in big letters. (The star was an afterthought when I was designing the first van signwriting - it seems to work - makes people look a second time)
Just booked my next year's Yellow Pages ads, I'm going to have my logo, followed by phone numbers and website, the idea is if people have noticed the vans, they'll recognise the logo in YP. I always monitor enquiries so it'll be interesting to see if I get any increase in YP response.