Personally I wouldn't go for an older one - stay with the one you already have...
As far as the car is concerned, it won't be as much fun as a mistress but will be a lot less expensive and even hold it's value. Further benefits are that your wife might even like the car (she won't like the mistress): there will be an initial period of doubt but in the end she'll get to love that wind-in-the-hair feeling.. and you'll love the fact that lot's of potential mistresses will give you the once over as you fly by.. well, that's what you might think, but really they are just looking at the car.
Mistresses come and go, a Morgan is forever.
