I have a 99 NA with auto. I consistently see 32 MPG (all highway driving). but I live in the midwest and it is flat, flat, flat,

Based on the trip computer ANY grade kills this number.

On truly flat roads at 60 MPH (Cruise on), computer reports 38.
ON a very slight grade (100 feet per mile), drops ...

The Shift light may or may not be a transmission problem, you don't state the service history, it would help to know when the last trans drain and fill was performed. also when/if the timing belt was done.

First thing is to get the codes, AutoZone or other will dump the codes for free, post those ...

It has been 20 years since I lived in a state with emission testing, Sorry to ask a stupid question.... Is it now practice to just read the ODBII port? NO tail pipe testing?

As expected, replaced the master control switch and all windows (including sunroof) work again.

Thanks everyone. Expensive part but easiest fix in the world.

I thought it might be worth showing what the switch looked like before cleaning, what a mess...'

thank you, for your responses, I have confirmed the roof is also inop so that leads to the switch , I attempted the cleaning (great write up , btw), no luck. I will order a new part.
The switch was really in rough shape but I didn't want to assume that was the issue.

I will let you know if that ...

Background: I wanted a Volvo so I purchased a 1998 s70 GLT a month an half ago, 30 days later it was totaled in a construction zone. I used the insurance money to buy another volvo. A 1999 s70 base with just 99,000 miles. I think I can be really happy with this car.

I have only owned the car a few ...