The problem with modern cars is that they're
notsimple anymore. The days of intuition, feeler gauges, simple continuity testers,corner motorshop testers (for sparkplugs etc), compression testers and the ubiquitous Haynes manuals are pretty well past, in my experience. These days- the ECUs run the car and, unless you can afford a decent diagnostic unit, fault finding tends to be consigned to dealership garages (and that's the way the likes of Honda, BMW, and so on, prefer it.
)
The days of getting all your spares from the breaker's yard are also long past, I think.
I used to base my car world on the 1960s Mini Cooper 'S" (970, 1071 and 1275cc), for decades and later the much maligned MG Metro Turbo, which could have been a great car but for lacklustre building practices, in an industry policed by barrack-room lawyers. Though I've owned many other types, and brands. Then, I shifted to Volvo, and had two 480ES examples, for looks, pop-up headlights and decent performance. These days, I potter round the Honda Civic and Jazz range just for sheer reliability. The need for scintillation disappears (along with many other things), with advancing years.
However,
One factor to consider, whether you want something sensible and 'future-proof', or something a bit unusual, and gutsy, is whether it can take E10 fuel. Many cars built before 2011 can't.
Classics that ran on leaded fuel (the old Coopers etc) needed new valves and hardened valve seats to cope with the switch from leaded to unleaded. The same will be true for more modern cars, with the planned eventual switch to E10 (10 % Ethanol) gas in the pipeline, so to speak.
Such mods could prove to be very expensive.
"Get your facts first, and then you can distort them as much as you please"- Mark Twain.