Having had a thorough going over by customs at calais last night, i certainly wouldn't want to carry anything abroad for anyone else unless I could see it was 100% legit.
I had trouble as although 6 of us travelled out to spain in the cali, 4 flew back leaving myself + teenage son to drive but bringing luggage for all 6 & the fewer occupants coming back seemed to set alarm bells ringing.
They also didn't seem to think that anyone would be mad enough to drive to spain just for a week.
As it was 2 in the morning I wasn't to quick off the mark & having answered no to "bringing any Alcohol etc ?" when the first thing they found on opening the fridge was a couple of bottles of wine, we seemed to get off on the wrong foot.
Once I had got the brain into gear though we had a bit of banter as to why I get a grilling for bringing too few people into the country & everyone else at Calais seem to being checked for bringing too many in.