This morning I was driving to go put air in my real low tire. Well it then decided to come off the rim a bit before I could stop. So i changed the tire and put the donut on. Oh I should mention it's an 04 Wrx. So I put the spare on and had to get on the highway. I then noticed the abs light and brake light turned on. Everything seemed fine and I was hovering around 60 (which yes is probably way to fast for a donut). All of a sudden the car seemed to violently shake out of no where. I slowed down and it continued to do so. I could feel it in the pedal and the shifter. I down shifted and it almost felt like the gears were rattling around down there grinding. I immediately pull off and turned the car off. After much swearing, panicking, and contemplating i made the executive decision to fire her back up. She started up and felt good. I got back on the highway and took it even slower and it never happened again.
More background. I have a bad rear O2 sensor that is getting fixed tomorrow. I also have noticed the past two mornings in the really cold weather that after about a half hour of driving when i left off the gas my engine starts to whine a bit. About the same whining noise you hear when you downshift. After the day warms up a bit it doesn't happen again. This also did not happen this morning.
Also, I work for a school and they have an autotech dept. I had them check it out today and one of the instructors couldn't find anything weird. It ran fine, fluids looked good (transmission, differentials, etc). He is thinking that it could be something funky with the O2 sending crap to the ecu for some offhand reason. He thought the car looked good. I trust him, just want to know if the internet has experienced anything like this as I know nothing about cars.
If you are still with me, I appreciate your time. I am sure most of the aforementioned things are unrelated but I'd rather give too much info than not enough