Lots of parts!

I am having some simple additions made to the aircraft.

1) Plug in jacks for the Bose ANR headsets (so I don't have to worry about batteries)
2) Replacing the 121.5 mHz ELT with a modern 406 mHz ELT that has position reporting (so in the case of a crash we can be found quickly)
3) Adding a gear alerting system that yells at you if you slow below a certain speed without the gear down (to help prevent gear up landings)

In order to do these they have had to take out a lot of the panels and other access points so just about everything is exposed.
One can easily see just how complex and packed a modern GA aircraft is. Of course much of the complexity is because they make so few and can't justify the R&D that automakers can to build tightly integrated solutions.

Of course, modern, well equipped aircraft are quite a bit more complex than the typical mass produced automobile.