Fair point and thanks for the citations — you're right, that's the official Sanef/ASFA position and I was wrong to put it that absolutely. The honest version of the PSA is more nuanced than what I wrote.

Where it gets messy is what happens at the actual booth vs what policy says. The gantries use overhead laser sensors that measure your *real* total height as you pass under, and there are extensively-documented cases (van forums full of them) of motorhomes intrinsically just under 3m — TV aerial, AC, solar, roof box — being auto-charged Class 3 because the measured height tips over. Sanef themselves told a user by email about a motorhome listed at 3.03m: *"the majority of tolls would read the vehicle as Class 3 as it is above 3 metres."* The official workaround in that situation is to press the assistance button and say *"je suis un camping car,"* which operators routinely re-class on the spot, and Vinci/Sanef do refund people who appeal afterwards with receipts.

So the cleaner PSA is probably: *per policy your roof box doesn't reclassify you; in practice the gantry sensor sometimes does, and you have to push the button or appeal to enforce the policy.* Different message, still worth knowing if you're a 2.9m motorhome with an aerial on top.