I have an April 2022 version of the new model which has now done 36,000km (22,000 miles) and have not noticed any reduction in fully charged range. In New Zealand it has 5 or 8 year warranty anyway although I'm sure they have fine print! A nice car, makes the old models appear very under powered...
I just installed the S27 Aero bars and K677 mount kit. The car has those same flat brackets but got around that by drilling and tapping an M6 hole in the brackets to fit the M6 grub screws. Fits nicely and can be removed easily.