There must be dozens of equivalent clips available, just visit (well, if you can right now) the Help/Dorman isle your local parts store.
If nothing else, use a christmas tree pin and a couple of zip-ties
Bad battery is my guess. The voltage is low and has caused the window positioning to reset.
Presuming they'll go all the way down if you hold the button, run them down like that and then all the way up again (holding the button). That should reset the positioning. But check your battery.
Given that the initial problem was a blown head gasket, I would think the best solution (and cheapest) is to put in a new/used head back in. I would further suggest you follow your mechanic's recommendation. He should be able to see if the block is OK.
Actually, it's true what he says about the CD. Why on earth would you want to look at that display instead of concentrating on DRIVING?
Obviously he's over the top in his presentation, but that's show biz.
Mazda provides the updates free too. It's the dealer that's charging you to apply the update... just like if you went to Best Buy to get a new OS/update put on your home PC.
But as you can tell from this thread, it's easy enough for you to do your own update for free.
Hmmm. Combative, you say?
Seems like a lot of possible solutions were posted... failed/maladjusted brake switch; leaking brake vacuum; failed/maladjusted transmission-nuetral switch (this happened to me); bad battery.
Try them all.
In any case, be that as it may, Parts/prices for a 2014 are here (you don't say what model/year your car is but it looks like a Gen1): https://www.bamwholesaleparts.com/v-2014-mazda-cx-5--touring--2-5l-l4-gas/body--exterior-trim-rear-door
As I said, you can probably reuse the clips and just slide on a new panel.
I know that my daughters Civic worked like that. I had to remove the plastic trim over the rocker panel at one point... there was a screw (or clip, maybe) that stopped the panel from sliding and that had to be undone...
No battery is likely to last 10-12 years. Yes there will be exceptions, especially if carefully looked-after, but the reality is that there are only three battery manufacturers in the US - Johnson Controls, Exide and East Penn - that make all the batteries for the various 'brand names'...
The limit sensing is at a far lower level than a high enough current to dim the lights. By the way, there are NO limit switches. That's why you have to reset the auto window function after you disconnect the battery - if there were limit switches, you wouldn't need to.
With the Directed...