Went to the m/h today to check on things and upon checking all my documents I found the Eurotunnel booking I had is for a car with roof rack and cycle rack, so I rung them and they asked for another £23 e.w. so I asked them to check my booking (all calls are recorded) on the date I made it, it stated it was a Mercedes/Euramobil/8mts length and 3.2 mt high, they booked it in as a Mercedes car.
Now that would have been some car with them dimensions, and they admitted they knew the vehicle was a camper as it matched my previous details, and was wrongly detailed and they would not charge for the extra tariff, so very kind of them "not"
Good job I noticed before I got too the checking in Barrier on departure date, that would have caused a queue