I hate cars. It hasn’t broken so there is no earthly reason to replace it. Plus, I didn’t decide to buy it so I’m certainly not going to criticise that decision as the person who made it drives the Poo-Go 99.5% of the time. (I rarely drive because of the side effects of the anti-nausea medications I take)
TL;DR don’t buy one.
Zzzzzz
'Zzzzactly, excepted with added brain fog.
Actually you can probably get a merc CL v12 for 6k. That will meet exactly none of your criteria
Do it. Doooo it.
Not breaking is a big selling point for me.
Mrs P only uses the car for shopping and a blue moon trip to see her parents in Plymouth.
This is all we use the car for. We do the shopping, the odd longer run and most of the time it sits there as we walk everywhere. Ours is a diesel too… 
. I would get a Milk Float except it is probably environmentally and economically more sensible to run this shitbox into the ground.
Oh yes I fogot to mention that it has the most uncomfortable seats in the Universe. Tail-bone ache after 20 minutes. Just excruciating on a motorway run. I usually hire something (anything???) else for serious driving.
OK, I’m not sold on that.
If I wanted arse pain I’d buy another kawasaki
Kia Rio, or an i20.
Quite dull, but that is not such a bad thing in this instance.
I looked at an i20 earlier, tiny boot space?
Not that bad. Similar to a Polo. Wife has the slightly bigger i30 which is quite bland, but seems quite reliable.
After you’ve driven over them, obviously.
Like I know what size boot a polo has 
Fiesta over a Peugot every time
Fiesta or Honda Jazz
I’ll direct her towards festers and jizz
Have you considered a nice Mazda RX-8?
Amazingly covers all of your criteria but two.
The answer’s “A Porsche” and fuck your roofbars. Always. Duh.
Look, cars are shit. If we must have one the only advantages over the bike are carrying a larger payload and having a stereo.
So a porker is just and over rated over priced stereo carrier with naff all payload.
Yankin yer chain, Porsches are for cunts 
At 6K get a Vauxhall or Ford - parts are cheaper … and you’re gonna need parts.