Anyone ever managed to successfully reject a used car?

Long story, short version.
Bought in early June. (A6, 3.0tdi Quattro SLine, FSH, 23.5kmiles, cost £22,000 consisting of trade in and personal loan)
Multiple visits to main dealer for following issues:

Drivers headlamp aiming very low (about 20ft in front of the car - repaired)
Wipers needed replaced
Yet car was sold with 11month MOT? Clearly not checked

MMI screen juddering on retraction (repaired)
Minor damage to bumper, noticed when car was uplifted (repaired)
Ashtray in rear door broken (fixed by me)
Music from previous owner left on jukebox (deleted by me)
child's sticker on rear seatbelt proving no valet
Promised wheel refurb but found residue of old wheel weights about 2 weeks after purchase proving they weren't refurbed.
Valet and tank of fuel to compensate
All within about 2months.

Fast forward to now, 6months after purchase.

MMI screen juddering again
Headlamp aiming low again (intermittent - seemed to be caused by cold weather)
So I Took car to different, more local dealer this time.
MMI screen mechanism replaced this time with no charge to me(but I think refused warranty)
I took the car in with the light faulty so the Technician could see it. Agreed it needed fixed. Headlamp servo replaced but no difference - new headlamp required. Warranty refused but 70% goodwill contribution bringing bill down from £1000 to £300.

Counting the wasted visits where nothing was done, and where my car was taken in to be valeted, it's been in the dealer, 8times in 6months.

Total repairs to car since purchase = probably around £1700-1800. I know the MMI repair was around £400. So it's a minimum of £1400 excluding the wipers, bumper repair etc

Currently, my car is with the local dealer awating instruction, while I, in turn, wait to hear what the selling dealer will do to help me. Phone calls to be made tomorrow as I chase them up and then arrange my headlamp replacement.

Spoke to Trading Standards today and it would seem, at least on paper, I may have reasonable grounds to reject the car under Consumer Rights Act 2015.
Just wondered if anyone had done it before, and how?

That's now a longer post than I envisaged but I've tried to keep it short.