Just finished watching Momentum, so I thought I'd mention it here. A few movies I've watched in recent times (mainly low-budget stuff) have had vehicles using the licence plate.
And for no other reason than curiousity I thought to google it, however, there's no reference to this and was wondering if anyone had noticed.
The number in question being: 3PCE419
Typing that plate number in on google brought up for me a listing on IMCDb (Internet Movie Car Database); here's the link: http://imcdb.org/movie.php?id=316272
It also appears that the plate has been used on multiple vehicles for multiple movies and originally was assigned to a 1992 Toyota Camry. Beyond that, I don't think there was any more significance. But, I could be wrong.
Sometimes, plates are used as reference to other movies. For example, the license plate on Bob Falfa's hot rod in American Graffiti is THX1138; a nod to George Lucas' student film. A different example would be a vanity plate like that in Con Air; the plate on the officious Colm Meaney's convertible reads AZZKIKR. It's more an aesthetic as part of the mise-en-scene of the film. Here, I think it was because it was a low-budget movie and they were trying to add a sense of realism by showing license plates. And in other movies as well that you have pointed out using that same alphanumeric sequence.
Hopefully, that helps you. I could be reading into this too much and there again, maybe not enough. One way or the other, thought I may shed a little light on the subject.
Cheers!