Fun car seem to be subjective...
Your basically saying that mod a lighter car and it will be more fun?
what about wheel base? chassis rigidity? suspension dynamics? ex. a light car like the old AE86 cant even handle that much power without being unstable to drive. This is true for most light weight cars.
Yes it is subjective, but I think most of us can agree that a fun car is one that you can take to near its (and your own) limits, in not just linear but lateral acceleration, and feel decent G forces in.
A shit car can be REALLY fun/exciting, but the bigger a car is, the less fun it is because it's missing that feeling of connectedness or danger. That damping inherent in heavier/bigger/more refined cars is what kills the feeling of fun, often.
When ads tout 'direct'ness, precision, feedback, etc... they're saying that the engineers tried to capture the essence of what 'driving excitement' (RIP Pontiac) is.
Wheelbase is less important than grip/progressive loss of, chassis rigidity is a good thing to a point - and that point was passed before the turn of the century. At this point, all that chassis bracing is just making the car heavier. You don't want a mushy, squirelly piece of shit, but at the same time, why not just seam weld everything and build in a roll cage?
The engineering of most cars today should allow them to handle twice their power (on the low end) without many problems.
It's nonsense to claim you can "just add power." At a certain point it costs more than the car and even assuming it costs you less to add the parts, it actually costs you more because the car's value doesn't increase with addons, it decreases.
Well, you can. Intake, exhaust are cheapish, give results. You can get a custom tune done to unlock some potential, run higher octane, bolt on a turbo or supercharger (on the extreme end) - most of these don't require any compromises to other factors such as comfort, handling, styling, storage/seating, etc... Naturally, more power will cost more gas though.
But to bring a heavier car down, you need to remove things. Once you get past easy things like a lightweight battery, spare tire, etc... where do you go? Carbon fiber body parts get expensive real fast, tossing out seats (obvious)... light weight wheels can be expensive. Then there's the fact that bigger cars more often than not have a higher center of gravity, leading to more body roll, or more stiffness in the suspension to counter that.
And once you've lightened the car? You may need to tune your suspension so that it doesn't get bouncy. Meanwhile, you're still probabably not more than 300-400 lbs lighter than when you started, but you've given up on many of the reasons you may have bought that car for.
