Since I got this car, the speedometer seems to be off after about 60mph. I really don't think everyone else on the highway is going 100+mph with me, so I'm guessing my speedometer must be shooting up at an unusually high rate. I have stock wheels and diff so I don't think it's that too. Is there a sensor that is off or needs cleaning? I'm concerned that this is also making my odometer run up too high as well.

Also...

I just passed smog!

 

Traffic is going 100mph with you. They are trying to look at the car.

 

Yea there's always this guy that flashes red and blue lights behind me. He must be helping to escort me to safely drive that fast. He likes to frantically wave at me the whole time too. What a nice fellow.

 

...anyone?

 

Do you have stock or aftermarket wheels? What are your tire sizes?

 

OP says "Stock wheels & Diff"

-Geoff

 

Could still have improper aspect ratio on the tires. If he has the original tires that came with the car, he has other problems.