I read a dev comment on improvability last week, and it didnt convince me it was significant.
From what i understand, if the chassis you built had +10 points beyond basic (cheapest = 0pts) then the new parts you build that season would have an improvement modifier of +10.
IIRC, if you hover over the bar which shows the base & max specs of what your about to build, or somewhere on that screen on the right side, it says something like:
100 base (what you started the season with)
+20 components
+10 designer skill (designers skill building that part so +0-20)
+8 improvability (chassis improvability bonus)
etc
So the first part you build using those specs would be:
100+20+10+8 = 138 base value (screw max for here)
If the 'good' part meant adding +10 base, +25 max, you'd have:
100+
30+10+8 = 138 (and max too)
So its not every single time you build a better part your gaining that chassis buff, but once, and i'd imagine we're talking about paying 3-4m for a 5-8pt supplier. Its not a huge amount, but is even 10pts of performance on 6 parts (4 with spec wings!) worth paying 3m for?? IMO its not. Double it, and maybe i'd think differently.
@capt - I actually thought you didnt get that payment if you failed to meet that target as a team that weekend, im not 100% sure its correct (and i wish i hadnt opted for 8th in my first Asia season cos i won with ease and was losing ~400k even with winning bonuses!), but im not sure how much of an impact underperforming would have and at what point you'd get the boot. Not 100% sure on this though, but do regret not having been more optimistic, but i was certain i'd get £0 if i failed to meet that goal, which hurt far worse than getting 50% more if i did hit that goal.