'S' hatch or convertible as 2nd car

It's while since I've been here as my wife's 03 Cooper just keeps rolling along and has now reached the dizzy heights of 29k miles from when she bought it new.

Anyway.....

I have just bought an 3.0 litre petrol X3 as I need to tow stuff and it eases my 'elderly' back so my 130i M Sport is surplus to requirements. The roads in the SE are so shocking and also so busy now that a 264bhp roller skate is pretty much irrelevant for the use I give it.

To keep a 'fun' car, I am thinking of getting a S and even going so far as a convertible as I don't need practicality - the X3 is for that.

I've just read the topic on the JCW and it seems I'd be going back to a skittish / over firm ride so I would discount that. I've replaced the RFT's on the 130 with proper tyres and that has made a huge difference but, for the mileage I now do (5 or 6k per year per car and mostly local) comfort is more appealing than outright performance.

The convertible is drawing me as the most I would need to carry is a briefcase or rucksack but are they really practical or too compromised. Don't care about the back seats being useless in either - I might even take them out of a hatch to improve load space if that's what I got in the end.

What mileage is reasonable without looking at impending costs?

Any views on either - it would be in the £7k region subject to selling the 130.

Thanks
David