Some corrosion, but they took it in and pit an undercoating on it. I've had rust issues though. Once while driving up to a job 4 hours away at 2am, I heard this loud boom, like I hit something. Pulled over (it was pitch dark and nobody on the road at that time) I didn't see anything, saw nothing unusual so I continued. When I got to the jobsite it was daylight, I looked under the truck and saw the gas tank hanging by the hose connecting it to the fill pipe. The strap and the metal plate holding the tank in place had completely rotted and fallen on the highway. So I've had my share of issues with the truck. Over the years I've replaced the gas tank strap, engine and universal joint. The 4 wheel drive no longer works but at this point I don't want to put big $$$ into it so I'M HOPING to baby it along for another year. We'll see
I had a similar experience with the spare tire holder.
Driving to work one morning it detached and went bouncing down the road behind me. I saw it bounding along in my rear view mirror. Fortunately, the car following me was actually back about 150 feet and was able to avoid my tire. Also, I was on a country road only going about 35 mph. At least, I was not going 70 down the highway. I could have caused a major accident.
This was about a 2 weeks before I turned it in to Toyota. So, I guess I would advise you to check that cable/bracket holding on your spare.