A very good question... I need to have a fiddle with the lumbar support mechanism in my drivers' seat - the previous owner must've been FAT - it's only ever groaned since I installed the seats; passenger is fine though.
I must admit I've only ever had a quick look at ELSA for information about dismantling/re-assembling the seats, and as I recall it wasn't too fruitful. If I can find some coal for the laptop I'll try again and post anything useful that I find. I wonder if there are any technical documents available from Recaro that might shed more light on it?...
Regards,
Rob.