Open the hood.
On your left, the ECU/TCU housing is just in front of the power steering fluid filler cap.
A tube at the top ducts fresh air from the radiator shroud. Another tube, on the lower left, passes down along a recess in the washer fluid reservoir. At that point, it transitions from round to rectangular, then passes toward the center of the car, within 1/2" of the accessory (serpentine) belt. It then curves downward, through a cutout in the lower engine cover. It terminates in an angle cut, such as to form an aspirator. This is an essense a "road draft" tube, similar in principle to what 1950's cars used for crankcase ventilation. When the vehicle is moving, a vacuum is established that pulls fresh air into the ECU housing (I assume for cooling).

I cut the tube above the transition point, then used a section of radiator hose (and hose clamps), to reposition the outlet well away from the belt, behind the right fog light. I used "ty-wraps" to fasten it to existing components.

For those not familiar with the problem:
Extending your front bumper over a common parking curb can deflect the lightweight lower engine cover. This dislodges the vent tube which is only retained at the top. Once underway, the rapidly spinning belt and alternator fan suck the dislodged vent into contact with the belt (which could happen several miles down the road). The direction of belt travel draws the duct into a pulley where it is shredded and demolished. The timing belt cover, directly behind the accessory (serpentine) belt, is only a lightweight plastic material, whereas the vent duct is a harder plastic. Shards penetrate the timing belt cover, and cause the timing belt to skip when drawn into the tensioner or drive gear. Since this is an interference engine, the pistons and valves contact each other, for all practical purposes destroying the cylinder head, and perhaps pistons as well. Unfortunate S80 drivers report $3000 repair bills to rebuild the top of the engine. I have read 9 such reports in the last 14 months on various S80 boards.