Current car: BMW Alpina B5 saloon
Bought this after I read this article
M5 vs B5 review and the following day out of the blue I got a call from the guy at the BMW garage who I'd bought my 330d Sport and 530d Sport off. I told him I wasn't really interested in changing just yet and jokingly said: "unless you've got a B5 in I can drive". He replied: "We have" as they had recently become a Sytner dealership, so I drove it the following day never thinking I would buy anything that expensive. The rest as they say is history. If you've ever driven a car that puts a huge grin on your face you'll know what I'm talking about. Power, poise, presence, superb suspension for such a big car and reasonable mpg for what it is. It'll outdrag an M5, keep your fillings in place and your flexible friend wont be worn out in petrol stations like the M car. I took it and the family down to the med over the Massif Central last summer and it was a joy to drive.
Next car: honestly don't know. Nothing else I'm aware of has as good a blend of performance and practicality. I couldn't live with a car that empties it's bladder before I do, and anything smaller and more nimble just isn't big enough for the family.
If you're hankering after an M5 you should take one of these out for a test drive too