When you say you’re only getting 11.3V, is this while the engine is running or turned off?

Slip a large sheet of cardboard under your engine bay and check for leaks.

If it’s not leaking and you’re losing oil and coolant you could have a bad head gasket. What appearance does your oil and coolant have and what does your exhaust look and smell like when the engine is fully warmed?

Alternators aren’t easy on Camrys after a certain model year in the 2000s. Used to be you could loosen the two bolts holding it, do the tensioner, slip the drive belt off, and undo the 14mm and 12mm bolts the rest of the way and wiggle the alternator out under a radiator hose.

Unfortunately on your later year Camry the radiator has to come out to get the alternator out. So your labor costs include the time a radiator replacement would take.

Here’s a coolant chart from Motorcraft that should help: https://www.motorcraft.com/content/dam/ford-motorcraft/en_us/motorcraft_global/products/lubricants/quick_reference_charts/antifreeze_coolants_english.pdf

Dexcool isn’t “crap”, I think the problems with it early on was with the materials used in the first cars to use it when it was introduced in the 90s, weren’t properly re-engineered from the IAT days (inorganic acid technology aka green). Dexcool is an OAT coolant (organic acid technology).

The materials that come into contact with coolant have to be properly engineered and have the correct composition to avoid getting eaten away or corroded from a given coolant type.

The yellow could be HOAT (hybrid organic acid technology) or OAT, the yellow color is just a dye, it is more important to know if your engine takes one or the other and choose accordingly.

If your car is FWD, sure, it’s fine. There’s almost an infinite number of tread patterns for a given class and type of tire that grip equally well. Tread pattern on an equivalent tire type has more to do with cosmetics and branding than offering any difference in performance.

Just steer clear of Hyundai and Kia, any other car you might buy made in the last 25 years should come equipped with an engine immobilizer.

Unlike Canada and several EU states, federal law in the US doesn’t mandate immobilizers, so Hyundai and Kia forwent installing them for a 6- year and 11-yeaemr stretch respectively solely because of greed. Meanwhile these very same models for the Canadian and EU markets had them.

You can put your key fob in a Faraday cage when you’re not driving it, if you buy a push button start vehicle. This helps prevent theft via intercept of your fob’s radio transmissions for the type of thieves who stand outside your home at night with an antenna.

I don’t understand how an oil change mess up could have led to any of the things you had done at the dealership.

Did JiffyLube simply not clean up areas where there was spilled oil when they took off the oil filter?

Usually when we hear of stories from quick service oil change places, it’s that they forgot to put oil in, overfilled the oil, forgot to put the drain bolt back in, forgot the gasket on the drain bolt, under or overtorqued the drain bolt, etc.