At the end of October 2019 I was involved in a bad smash with a lorry (you can see what happened here: https://youtu.be/OCCvAkWcZ6k).

My insurance (Markerstudy - via Adrian Flux) decided to fix the vehicle, and the vehicle was returned to me mid-december.

The car was fine when I received it back and the work seemed to have been done well.  New bootlid and components, new rear lights, rear bumper, crash bar and new exhaust.  Front grill was also re-fitted.  However, I then started to have issues that the car wouldn't start every now and again when I pressed the button (keyless start) but would 2nd or 3rd time.  I would just get a clunk sound and no crank.  The car was booked in to be looked at, but before this happened the car stopped starting completely and the RAC had to attend.  They tested battery, keyfob, keyfob battery and signal, and checked all round engine.  The tests did show there was a electrical drain somewhere when car was switched off but it was not able to be located and wasn't always present.  There were no diagnostic codes recorded.

As the car eventually did start RAC advised me to take it back to the garage that did repairs (Evans Halshaw Bodyshop) as there may be fault caused by them or further crash damage so i left the car at the garage.  The garage refused as they wanted it to go back through insurance although insurance argued it was garage's responsibility if the fault lies with them.  

Anyway, I have now collected car back from the garage (once I got it started again) and insurance have now spoken to garage to get it re-assessed.  This is where my next problem comes in.  When I collected the car back (the garage hadn't done any work on the car) the boot now won't open by pressing button on the boot (only unlocks with key) and none of the passenger doors will now unlock (they can be opened from the inside).  Drivers door will unlock and lock fine.  I'll be taking car back to bodyshop tomorrow who did the repairs as they and insurance have been in touch with each other now to get this sorted.

It's been mentioned a few times when I've spoken to garage they feel the starting issue is unrelated (car was perfectly fine before crash) and now the door and boot issue has happened at the same time of this worsening.  

It's a 2015 Ford Focus Titanium, 1.5 TDCi.  Does anybody have any suggestion or advice on proceeding with this?  

Thank you.

Ok appears the unlocking of doors and boot may be an anti-hijack feature. All the doors and boot can unlocked with 2 presses of the unlock button key. Only driver's door opens with 1 press of the key. It never used to do this before, but the RAC did try and re-program the key to the locks so it may have been then when this got activated and is a feature I'm happy to keep. Just got to sort the starting issues now. Annoyingly, it started first time every time at the garage but they will be keeping it to look further into it. 

So think this will finally be resolved. It was in colder weather the car wouldn't start and after being back to garage now 5 times with nothing found, it was booked in for a service and glow plug change. Anyway it gave up completely the day before the booking and RAC came and was able to start by towing it. Diagnosed as starter motor failure so hopefully this will resolve the issue as it's now being replaced. Just wondering what people would recommend in regards to keeping this car or swapping it following the crash? Could starter motor issue be related to crash and is there anything else I should be wary of? 

Put a volt meter on the battery negative and touch it to the engine block. With the key turned on you should get around 0 volts. If you read any voltage higher than a fraction of a volt you have a bad engine ground wire. The crash may have weakened an earth grounding stud. All sorts of problems can result - doors not locking, starting problems, lights turning on off. Check visually for any damage to earth wiring, a wire that is torn but still connected could cause these problems. Check the grounding bolt is tight.