It reminds me of the time when I was in college, we drove down to Spain. Coming back, we went through Andorra, and went mad on buying whiskey etc. When we were leaving, heading into France, the French police/border guards saw the Irish plate and pulled us over. Their eyes lit up when they saw the bottles of whiskey! We had to pay a 'fine' for each bottle, then, if we wanted to keep them, pay even more. As it was the end of the holiday, we had little cash, so we left the bottles with them...
Kind of a foreshadowing of the Brexit customs since the UK became a 'third country'