Car appreciation... the aesthetics, the engineering, etc

I had a browse on Autotrader - is it worth looking a newer car from a less fashionable brand? You can get a 20k mile 2019 Insignia estate for similar money to a 2017 Superb getting on for 40k miles - gives you 20k 'free' driving?

Obviously anything other than buying new and keeping forever, or bangernomics, is hard to justify from a pure financial perspective. Just do what feels best and don't worry about the cost too much maybe?

It's so hard to say.

I hesitate to reference my own car, but it's just needed servicing from ~35k to ~50k. It has DSG so I spent a bit more on a major service to make sure the oil was changed but nothing else. In my MINI that my folks now have the clutch (iirc) went. From BMW that was ~£2.5k. I'm sure you could get that cheaper from an indy. It's also had a new battery which again was reassuringly expensive from BMW.

With the wealth of info online now, you can usually find out about thinks like the Mini clutch, or timing chains, etc. I feel like most of these big bills are around £2k and you should expect 1 or 2.

Goes without saying that cars like Mercs or BWMs are going to cost a lot to repair just from a parts pov.

Generally speaking, modern cars use a lot of plastics and composites in the engine. Cooling system, water pumps (often integrated into larger components) valve covers etc. Heat cycles kill them and after 5 years or so they can start to fail. Also you get to the point where the suspension might need a few bushes refreshed or dampers might need replacing. It's not end of world stuff, but it's necessary to keep the running. Personally I'm ok to fix things if I'll be driving the car for 5 years or so.

My own experience is with 2 Audi's. A 2010 A3 that had the dreaded oil consumption issue. Full Audi service history meant that even though I was the second owner they covered the cost of repairs. $11,000 thanks very much. Other small things failed. The egr diverter valve cracked... Plastic. And and a/c components. Not huge costs, but not exactly cheap. Also the brakes needed discs and pads which was around $1600.

My current A4. No major issues so far. It's a 2015 and again, bought second hand with full Audi history. Just maintenance. Tyres, went fancy with pilot sport 4s and new brakes. In two years of ownership service cost and tyres has been about $4000. I don't keep track of the fuel, but it's a lot!
Oh, I did have a hid headlight ballast replaced under warranty. A $1200 component! This is all relevant to Skoda as they share the many parts.