Just a quick tip to pass along for those unaware (as I was until yesterday). Have you noticed that the front seat backs on our 200s can be somewhat angled in toward the center of the vehicle? The cause of this is usually* due to slippage of the shaft that drives the gears that control the angle of the seat back. Rather than a solid arm between the gears, Volvo used two separate, smaller gears with a shaft crimped onto the gearshaft splines. This shaft, based on my observation and supposition, will bend with time and then can slide left-to-right on the gearshafts. This allows for only one of the two gears to actuate from time to time, resulting in the crooked angle of the seat. This can be cured by either:

1. straightening the rod to ensure that it contacts both splined surfaces, or
2. use the play in the rod to slide it from side to side while turning the seat-back-angle adjustment handle to even-out the seatback angle.

I'll see what I can do to get a few pictures together to better illustrate what I'm trying to discuss, but hope that this comes in handy for someone else here.

Cheers,
Zach

* The other cause would likely be seat frame fatigue/damage.