Looking for a used Audi A4 for sale, any common issues?

ive been scrolling through marketplace and autotrader for like three weeks straight now and my head is honestly spinning because i need a car by the first of the month for this new commute into philly. i have about 17k saved up which i thought was plenty but everything seems so overpriced right now and im terrified of buying a lemon that explodes two weeks later.

im basically torn between two specific ones i found locally. the first is a 2015 a4 premium plus with 72k miles and it looks super clean like the guy definitely babied it but its the older body style and i keep hearing horror stories about the b8 engines and oil consumption which makes me so nervous. the other one is a 2017 a4 with the newer interior and tech which i way prefer but it already has 98k miles on it and its right at the top of my budget at 17,500. i love the apple carplay in the 2017 but that mileage is scary for that price.

im leaning towards the 2015 because of the lower miles but then i read online that the 2017 is actually more reliable because they fixed some of the major engine flaws from the earlier years? but then nearly 100k miles on a german car sounds like a recipe for a 4000 dollar repair bill any minute now and i cant afford that right after buying it. its for a 45 minute commute each way so i need something that isnt gonna leave me stranded on the schuylkill during rush hour. my last car was a civic that never had an issue so jumping into the audi world feels like a huge risk.

what are the actual common issues i should be looking for when i go see these in person this weekend? like are there specific things like water pumps or timing chains that i should ask the owners about or check in the service records? is the 2017 with high miles actually a safer bet than the 2015 with lower miles or am i just overthinking this whole thing...