Intentional or not someone should have noticed it.
TG's producer on the subject:
The truth is the first time we realised the plate could be a problem was on the third night of our shoot in Argentina (19 September, I believe), when Jeremy was scrolling through Twitter and spotted a comment on one of the auto fan sites, next to a photo of the plate. I remember his surprise and concern.
There are other witnesses to this fact. In fact, one of them – a mechanic we were using for the first time – has written to the Telegraph Letters page stating he saw Jeremy’s reaction and that it could have been nothing but genuine. (Weirdly, although he’s chased them, the Telegraph has so far not bothered to print his letter.)
Knowing this could be a problem, our office spoke to the local authorities in Ushuaia, the town where the war issue was most sensitive, and where we would end our trip in ten days’ time with a massive game of car football. We agreed with those authorities that the plates would be removed before we entered the town, and it was at this point – not before we left London – that we decided to get the BE11 END plates made for Jeremy’s car for the football match in the town.
Before we entered Ushuaia we duly removed the H982 FKL plates from the Porsche. For a day or two, the plate on the back said H1 VAE (the plate left there, underneath H982 FKL, from when one owner had privately registered the car). An advance party of our guys had been in there for a few days already, prepping the football game with no problem whatsoever. The local ski resort was looking forward to us filming there too.
There was nothing in the air to suggest trouble was brewing until the Argentinian veterans arrived and kicked off. We apologised that the existence of the plates earlier on would have caused offence. We explained they were now gone, and that they had not been a deliberate act. They didn’t believe us, told us to leave town or face the consequences, we did that very thing and drove into a night of violent terror.
Wasn't really any more they could do...