I have an 07 plate GS4, I would say the best motor ive ever owned!.
I have trouble with constantly having to pump up the seat to me preferred driving position. It drops down after couple days. Any body had this trouble before?. I presume its the height cylinder or the handle that's leaking internally. No oil is ever found below the seat.

old subject,, some cured it by chocking the control lever, apparently everytime you enter the car you press down on the lever lowering the seat.
others say that didnt cure it

someone bought a scrapyard electric base to solve the problem At work
At home

"I can't always believe facts I read on the web" - Charles Dickens

winner by default of the tractor vs caravan race

I cured mine by removing the plastic handle just leaving the metal stub. The handle doesn't depress now when leaving and entering.

Thanks Guys.
seems it is I touch the handle each time I get in , I will remove the handle cover

Yep, I have to keep pumping mine up, when I get out of the car I slide over the handle and push it down, took a while to figure out