Sorry to learn of the split sir.
I had a 2004 BMW e46 M-sport coupe 2.2 litre petrol 170bhp that I loved (regret selling it last year). Easy enough on the petrol (25-30 mpg) and a lovely looking thing, good enough room in the back depending of number of kids but plenty big enough for 4 adults.
I also like the look of the Volvo V70 Convertible, always looked appealing.
Good luck, I imagine plenty of nice older cars available for that money.. why not get in touch with Dave O'Sullivan of this parish? think he's London based.