ok guys, time to get serious: book the ticket for the eurotunnel

!
i've never done that before, so i don't know how strict the guys at the check-in are, therefore a couple of questions:
the "vehicle-type category" on the booking website gives me a couple of options, the ones interesting for me are either "car-based van" (height 185 cm and smaller) and "van" (height more than 185 cm). the van i'm planning on bringing over is higher than 185 cm, but of course the van category is more expensive than the van-based category. just curious: are they going to check the height of my vehicle at all? or would you go with "car-based van" and play stupid when asked?
@erik: which "category" did you choose?
let's suppose i choose the "van category", then i'm being asked whether i intend to carry a load greater than 3 cubic metres. i guess the load of the cabs i intend on bringing back is bigger than the given number, but when i choose YES, i get the message that for safety reason i'm not permitted to carry a load bigger than 3 cubic metres and that i should reduce the load

! can i simply ignore that question and click on NO?
puh, i'm quite nervous when thinking about what's lying ahead of me ...