I'm curious if any of the front-wheel-drive Volvo owners on this forum (or the 900 owners) have considered intstalling a relay and a resistor pack to the primary cooling fan? A few considerations:

1. A relay that would turn on the fan and circulate air through the engine bay and the radiator for a set duration of time after the engine is shut down (typically 2 to 5 minutes). You could also wire up a manual over-ride switch to the cabin so the driver could either disable or manually force it into operation. Having the car automatically cool itself would reduce/elimiate the "heat soak" cycle that the engine gives itself after it shuts down and the air stops moving through the bay. -also reduces nylon fatigue and embritlement as engine bay temps are reduced.
***Vehicles where used previously: Many Chrysler vehicles in the late '80s and early '90s. My brother's wife had a late '80s Plymouth Horizon with this setup.

2. Install a high current resistor between the ignition switch and the cooling fan, forcing the fan to run at a low speed anytime the key is in position 2. This would help reduce the temperature cycles in the engine bay during operation.
***Many GM vehicles in the '80s and '90s had a similar system set up, but using temp probes in the block to trip activation of the low & high speed resistors settings.

3. Install a temperature probe in the lower radiator hose (an on/off probe with a lower "on" temp than the standard engine temp probe), that slaves a relay, which kicks on the cooling fan through a resistor. This would allow the engine to start cooling itself sooner with the fan running at low speeds, and maintain a more constant temperature rather than the fan running at high speeds for short durations.
***Volvo used a similar setup in their early 700 vehicles to activate the pusher fan mounted in front of the AC Condenser (on vehicles that did not have the temp sensor in the radiator). I don't have the part number handy, but there was a 2.5" lenth of ABS plastic that you spliced in the middle of the lower radiator hose that had a temperature probe in the middle of it. This was used to trigger the relay & fan. This was used to augment the cooling of the standard fan behind the radiator.

God bless,
Fitz Fitzgerald.