Have taken my Long wheel base thru many a car wash, only once did the wheel on the back cause a problem, the brush hit it and the machine stopped immediately. I went in and complained and they apologised and gave me a refund. some car washes have notices saying they are not suitable for certain types of car. so it is probably best to ask first.
Just remembered, dont forget to fold your aerial down and pull the wing mirrors in!
I also drink Port and I'm not ashamed to say it!
Me Truck