My wife is a property manager for a real estate company (she manages their commercial and residential rental and lease-option units). She has a Yukon Denali that is wrapped (completely, bumper to bumper) with the company logo and information, and 3 of her 'main' maintenance/repair guys have Ford Explorers with the same. They also just bought a new Chevrolet Dually pickup that is at the shop to also be completely wrapped.
It creates brand recognition. People tell her all the time "Oh yeah, the place with the green SUV's!". The Yukon she doesn't take home, because it's only any good if it's being used! But whether she's driving to the courthouse to deal with evictions or meeting prospective tenants to show a unit; she drives that wrapped Yukon (she only drives her car to/from the office). If she isn't working, there's an assistant in the office who will use it! It creates brand recognition. Same as the maintenance guys going to do repairs, cleanouts, or maintenance- all around the towns they have rental units in (basically the whole county), you'll see those wrapped SUV's. The 'real estate' side is the same way. The owner of the company has a wrapped escalade, his wife drives a wrapped Malibu and they have yet another Yukon Denali that is wrapped for the other 'main agent'. People know the company because they have rolling billboards everywhere.
So people may not look at the wrapped truck and think "Oh, gee, I need to call them"; BUT, when they ARE looking to buy or rent a property, it'll be tough for them to get my wifes company out of their heads! That's marketing! Same reason TV commercials are played over and over and over- they want to be in the back of your mind.
I think mobile detailing rigs that are wrapped and/or logoed (and spotlessly, flawlessly clean 24/7) is the way to go. Even if nobody sees you and calls you immediately, you'll develop a brand image and recognition.
