For what it's worth:
I've just come off a 4 year deal with Audi... A4 20.T S-line - the worst experience I have ever has with a car (Brilliant when it was working, but boy did it spend time in the garage!) Seat used to be on my options (company car), but every time someone priced one it was always cheaper to order a VW due to resale values. The GTD I have ordered is cheaper than a series on a monthly basis and cheaper than a Focus, A3 by, about £80 a month (£30 cheaper than than the Focus) mostly to to with resale values. The reason is, I am told, that 2nd hand high spec Golf Diesel's are so highly sought after