Volvo 2007-2016 Volvo V70 should fit your requirements.
I can easily get a 1255mm wheelbase 29er in the boot of mine with wheels on and front seats in position for a 6 foot driver.

D5 for 215bhp, £180pa tax, long term average of 46mpg over 50K miles that I’ve had it.

Can be found in 4wd normal version, or 4wd xc70 version if that is important to you.

Cheers all for the suggestions, leasing is also now an option – you can get something very decent for around £250 a month, with a towbar for a bike rack. I’d be saving £100 a month on fuel based on 10k miles per year plus the £50 VED so cost would only be in the region of £100 a month.

Although I’d prefer not to have something on monthly cost/a debt towards it, not having to worry about MOT/rust etc is a big appeal.

There’s 3 distinct options:
Cheap £1500 1.9tdi octavia with 150k, run it for a year or 2, or until it dies (so probably 5+ years!).
£6000-8000 for a 2011ish car with 60k miles (for eg forester diesel) – would mean about £4k extra funds from either sale of my motorbike (which I’ve barely used in the last year) or a loan over 2 years at £190 a month. Still in the age where it could have big bills.
Lease a small SUV with a towbar, £250pm with £1500 initial payment, pocket the £2-£3k from the sale of the Legacy. Give it back after 2 or 3 years.

I’ll do some sums to see what works out best.

FYI and for all the doubters I just measured my v70 load area. It’s 188 from the back of the drivers seat to the tailgate. With the front passenger seat flipped forwards. It’s on a quick release, it jumps up to 210 on the diagonal.
I pick up the bikes by the crank arm slide the bike in then rotate the bars about 45 degrees. So all the length you need is rear wheel to front axle distance.