Pearl white GTA heading west on Chiswick Bridge London just before Mortlake crossroads, it had an irish plate and the driver was sporting a grey beard... It was all a blur for me as I was driving my mates VX220 turbo - they're rather quick for a vauxhall. Can't remember the exact day last week as it was a boozy one!
That's two i've spotted now, not that I'm actually a spotter...