look at tires and wheel bearings first those are the two biggest causes. certain tire treads can make more noise, but check to make sure they are installed correctly and that they don’t have weird/uneven wear. if they have uneven wear, that points to an alignment or suspension issue. if all checks out on that front it’s most likely a wheel bearing

with all automatics never ever ever get them flushed, just drain and fill that’s plenty enough. as for mileage intervals id do cvts and dcts every 30-40k miles, however the upper end for pretty much all autos is every 60k miles. if you’re looking for official recommendations good luck, many automakers don’t specify transmission mileages anymore as they claim the fluid is “lifetime” which is definitely not true. but stick to the general rule of thumb of 30-60k miles depending on transmission

unfortunately yes. vehicles with direct injection use a low pressure pump in the tank and of course the high pressure pump near the fuel injectors. when you run the tank low, the low pressure pump has to work harder to supply consistent fuel pressure to the high pressure pump, meaning it is working harder as well. however because the high pressure pumps run at over 1000 psi, straining them due to low fuel pressure is fatal much more often than a low pressure pump. it’s also more fatal for high pressure pumps as they somewhat rely on the fuel to lubricate the pump, much more so in diesel vehicles. so just make sure not to run it too low too often and all will be well

well hyundai has lower general quality than toyota, they don’t last as long and have more problems in the same time frame than a toyota, which contributes to depreciation. that’s why used corollas can be so pricey is because they are well built cars that don’t have problems as much, where hyundai/kia are much more hit or miss. some people have over 200k miles on theirs, while many many others have issues ranging from electrical gremlins to destroyed engines, even on near brand new cars. another reason is that hyundai/kia actually own their own steel companies, meaning they can get certain high cost materials for much much less than other car manufacturers