Got a bit of an alternative suggestion for Dave's management and care- I do appreciate that this is not likely to be advice that most on here would agree with or follow but can honestly say it's working well for me so far and I'm not about to change
I think the problem with Dave is that you are actually looking at him -
solution to my Land Rover ownership is that you ignore anything and everything that doesn't make a really loud noise or means that you can't drive over 10mph - you never look underneith because you'll see horrible stuff and you certainly never open the bonnet. At that point you get the thing making the loud noise fixed but studiously ignore everything else.
Now some of the guys will tell you that this is the wrong approach - that prevention is better than cure , that maintenance is vital etc etc - but it's twaddle - Beast gets a twice yearly oil and water top up and a service ( if I can afford it ) yearly . Beast gets a loving caress on her steering wheel to let her know I appreciate her working but I refuse to give her little aches and pains and grunts and groans any attention - its called operant conditioning - I ignore behaviour I don't want - breakdowns and reinforce behaviour I do - ie working with a gentle pat and a nice word.
I also take this approach to carrying spares- carry absolutely none- bugger all - and have needed none and if I have there has been the nice Mr AA man to fix it . I know if I carried a load in the boot- she would take that as a sign that it was acceptable to breakdown and do so because she could . Don't carry 17 spare wheels as in 29 years of driving I've only ever had one puncture - so , atm carrying just the one spare technique has surficed
Now so far this approach has worked - it worked for the US Army - don't ask, don't tell and Im using a similar approach - don't look, don't breakdown. I feel that this is something you should consider when looking at your further interaction with Dave.
Dave reminds me somewhat of a difficult teenager and boundaries need to be put in place and he needs to be taught who's boss - you .