Our old Citroen XM ran around with a French front plate for a few years, after the plastic front one was smashed by an idiot Frenchman who couldn't reverse park properly. It went through a few MOTs with no problems even though the spacing was a little unusual and never attracted Police attention (the space between the letter and the digits could have done with being a tad smaller).
Things your holiday phrasebook doesn't include: Negotiating with "M. Minute" for a new front numberplate! :lol: