Maximum outfit length

AndyRT

according to the government website gov.uk there is a maximum permissible length of 7 metres for a trailer being towed by a vehicle weighing less than 3.5 tonnes (Quote from website shown below in italics).  Surely that outlaws the towing
of long 'vans (such as the Elddis Crusader, 8 metres long) even by meaty vehicles such as LR Discovery, VW Caravelle, Volvo XC90.  Indeed are there
any tow cars that exceed 3.5 tonnes?  

"Width and length

The maximum trailer width for any towing vehicle is 2.55 metres. The maximum length is 7 metres for a trailer towed by a vehicle weighing up to 3.5 tonnes (3,500 kilograms)."