Hot, hot is relative! At least it rains where you are where as we do not get the rain. Signs of the future, I'm afraid! So on to the current things we can change!
Lots of guessing involved so keep that in mind but the wipers may be as simple as not knowing the controls real well. Maybe suggest they were on some form of intermit setting until you changed them? My wife's car has a habit of doing the weird wiper thing but only when I drive it! Honda and Ford do it opposite ways, so maybe just watch that one?
I've seen some posts on AC squealing and have thought to mention taking a look at the fans as they start, to try to spot which fan, motor, or shaft might be squealing. Then there is also the idea of using some type of spray lube on things that "might" be squealing as lube rarely hurts anything and often does lots of good things. I'm slow to take things in for repair before knowing what exactly I want fixed as I do take care of my money far better than other folks might!
That might lead me to spray lube on any point that looks like it might have a bearing of some sort, while also taking a look at things like fans which are mounted on shafts. Lots of different styles, sizes, etc. but if they have any form of set screw that might be a bit loose, it can be as simple as they slip a bit until the momentum gets them fully moving. Squeal like a mashed cat until they get moving? See if anything seems loose on shafts, might tell you something easy to fix. A fan not turning full speed might also make it less efficient at cooling?
Random guessing and hoping for a cheap fix, does sometimes work if I go slow at the game. If I'm patient, lubing one point at a time lets me know when I've found the right one that's squealing but doing them all at once gets results quicker.
Rv's tend to teach me patience!
We love Tyler State park for "on the route" stops! Looking forward to them getting rental kayaks out again but that is filed under "patience" also.