A5 Cabriolet - Prognosis for deprecation?

[TheWineLake]

Crystal ball time!

Toying with the idea of an A5 - maybe a Cabriolet. However there doesn't appear to be an Ultra yet, so I would hold off until then.

However, are Cabriolets likely to be more or less vulnerable to the dreaded depreciation than tin-roofed cars?

[TheWineLake]

...I've been looking at AutoTrader to get an idea of depreciation of A5's in general vs A6.

It seems to me that the A5s hold their value better - i.e. 2 year old models are rarely below £20k, whereas sub £20k 2-year-old A6's are quite common. I'd go so far as to say that although their price new is about the same (talking 2.0 Ultra here), the value of a 2 y.o. (non ultra, as they're new) A5 is about £2k more than an A6.

Only a fairly quick review, but is it fair?