Just a suggestion for the next big update:
-Platform update/change with facelift.
It has been done IRL:
Peugeot 405 1992 update - In 1992, the range was facelifted. While the changes were deep, including a modified bottom plate and chassis structure, the design was almost indistinguishable from the pre facelift model.
BMW E24 1982 facelift - In 1982 (model year 1983 in the US), the E24 platform changed from the E12 5 Series to the E28 5 Series, resulting changes to exterior styling, engines, chassis, suspension, electronics and the interior.
The quality sliders may be how it’s done. No change - same. Change - new platform, longer engineering time.
Another option is to have the option to move the reliabilty slider while the car is in production. This may result in reengineering of the car. Of course it’s going to take less time as it’s the same car, with a few changes.