Re: Transmission issue
To find the transmission model it's stamped into the bottom of the pan if you can crawl under the vehicle. It might be coated with road grime just to warn you.
If the transmission fluid is anything but a nice red colour - change it. If the trans is starting to burn (knowingly from heat), then the fluid should be changed at a minimum. Burnt fluid smell generally means you need a rebuild. There's not much you can do to try to save a transmission.
Some Taurus models had a rather short final drive. say 70mph is 2500rpm in top gear. If you perpetually drive with several passengers at 75+mph the transmission should be serviced every 40K miles. EPA mileage estimates, and manufacturer basic schedule services peg the vehicle at a top speed of 60mph as per federal regulations. Any faster and mileage suffers, along with added heat in the transmission, bearings, etc that need to be serviced sooner.
The TPS (throttle position sensor) is also known for causing transmission problems, and is often misdiagnosed by even the best transmission shops. A bad TPS (about ~$50) can cause sudden downshifts, upshifts while staying at a steady speed. The wind isn't necessarily the problem on the downshifting to redline.
As mentioned, you'll need to pull the codes. Places like Autozone will check codes for free but you'll have to drive the vehicle there. Good luck!
'00 Durango R/T 360ci 290hp (modded); 138,500m
'06 Pontiac G6 GT 3.5L 220hp; 44,000m
'12 Chrysler 200 Limited 3.6L 283hp; 13,000m
'99 Taurus 3.0L 2V Vulcan 145hp; 154,300m - Traded
Amsoil in all vehicles!