regarding bolt ons and aero
its not the individual components, its how you put it all together and make it work. the engineering smarts and development you speak of are in making the entire package work and tweaking the setup to go from having a 1:33.5 second car frist year out to having a sub 1:30 car some time down the track (hopefully!)
But to be clear, there are many small areas of innovation going on constantly, sure they may be minor and perhaps not earth shatteringly original but do you really think the top teams are going to stick their concepts on a forum for the great masses? those are hard fought gains and are closely guarded secrets