I've previously mused on things I'd like to see at my ideal wedding reception. Some people consider limos to be the best way to say, "I'm coming and going in style." More recently, people have opted for the SUV-limo.
If you're having your big day in London, and you want to show people that you are living la dolce vida, then perhaps you ought to consider this. Nothing will accentuate that blessed day like rolling up in an APC.
And hey, if that drunken relative of yours happens to make a scene at the reception, you can always lay a couple of mines behind his car. Or just crush it. Y'know, whichever is more convenient.