i have had a touring caravan for approx 30 years .mostly new .about three years i had a very bad experiance of a snaking caravan of which i could not find out why .until i was told to check the wheel balancing on my caravan and found them to be way out of balance .since then everytime i purchace a new van i have the wheels balanced .i have just purchased a swift challenger 520 .this time the wheels were so much out of balance they were dangerous .i have contacted swift and they e/mailed me to say that the reason they dont balance the wheels before the vans leave the factory is they are put on and off trailers whitch unbalnces the wheels ?? he also said it is up to the dealer to offer the service .we are talking on 10 pounds to balance the wheels .a small cost when you think it could save lives .. i look forward to your responce .yours truthfullly w.r.farley