Spinning knob on driver seat and lower back support?

[Craigie-B]

I have ph2 172 front seats and on the left side theres a knob and all it does is spin - whats this actually for?

Also I find these seats make my lower back ache when I drive for more than 15 mins in the car - do any of you guys get this?

Cheers

 

[AlexW]

Lower back support (lumbar support).

Possibile that its broken as lots do.

 

[Dr HMS Derv Destroyer]

That's why I'm glad I've left my dynamique seats in. Hate the sports seats!