I would like to compile a simple list (not your entire story) of common and/or infamous small car problems, specifically to their model type. Let's say ideally a rough range from 2010's till now (but can be old as 2000's). Happy for this list to include recalls on previous models.
I'll start with some general examples:
- Corolla Sportivo - Gearbox issues.
- Peugeot 206/306 - Coolant/water tank leaks & electrical gremlins.
- VW Golf - DSG.
- i30 - Aircon & condensation.
Edit: This list assumes you are servicing it regularly/properly, and not thrashing your car.
Might not be as extreme as OP's issues but my current car a Honda Jazz My 2019, had the battery die after 22 months, thankfully the battery was still under full warranty and was replaced for free.