One mans meat is anothers poison i suppose. Having owned in the past, much higher performance petrol and diesel cars with the corresponding higher running, maintenance and insurance costs, the enhancements ive made have surprisingly, improved the ride quality through lowering and stiffening the suspension. Increasing tyre width whilst maintaining rolling radius has had a slightly detrimental effect in fuel economy due to increased tyre width no doubt but made a noticeable difference on grip levels, particularly in the wet, providing greater margins of safety should something unplanned occur Plus i prefer the look of the alloys over the standard ones. Privacy glass is there for reasons of privacy and the fitment of a stainless steel aftermarket exhaust whilst an asthetic choice, appears to have released more mid range torque than standard, however there may be some placebo effect!
Personally, i prefer the look and feel of my Jazz now.
Choosing a car is a very personal thing and peoples attitudes to them and why they drive them are equally diverse. Personallisation starts when choosing your colour, the choice to make further changes can be driven by aesthetic, performance and or any one of a number of reasons, thankfully, or its beige trousers for us all! Oh i also wear a nice belt with mine and its reversible.
I view my car as more than just a means of getting from A to B