I feel for you Paul. It sounds to me like what ever you do will almost certainly end in tears.
I hope you don't mind me saying this but your wife doesn't sound very keen on the £57k Cali idea. Her counter suggestion sounds like £20ks worth of disinterest to me and anyway if you were to go down that route, you'll probably have to chase the chickens out of it before you can start living the dream. At the same time the Astin Martin will be sitting on your driveway, glaring at you whilst demanding constant access to your wallet.
On the other hand you could ignore your wife, go for your dream Cali and never hear the last of it.
What you need is a cunning plan.
How about suggesting that you both start looking for suitable vehicles. Go and have a look at a few old DB9s and Calis. However make sure that you both visit a good VW Commercial dealership and get a good salesman to properly talk you through the California "purely for research of course"
. The Cali has a lot of showroom presence and can almost sell itself. Might I suggest you visit SMG at Tonbridge as they currently have a new T6 Ocean 4Motion in their showroom. Make an appointment to speak to Laine Watts who must be about the most knowledgeable and enthusiastic salesman that VW Commercial have. He is a true Cali enthusiast and has sold us two Calis to date. He is a very charming man.
Following this process, if you wife were to suggest that you should buy an uber gorgeous Cali and forget your silly DB9 idea, make sure that you rent one first to ensure that you both enjoy the glamping experience before laying down your hard earned.