Quite an interesting history, TEIN Flex Z (and then above that MCA Blues, though they're an Aussie business) coilovers is what I see a lot of people suggesting when it comes to upgrading suspension.
Bought mine a couple months ago from a dealership in South Australia, which is over 2,500km from me, sight unseen, only went off pictures from carsales.
As such, I didn't get much of it's history, dealership didn't care even though they run a fairly niche JDM dealership, so don't know about anything that's been replaced that isn't regularly replaced, or obvious. It has got an engine dampener, and a K&N air filter, and once I get my open license in less than a years time the plan is to pop a supercharger on top.