I've hit 120 quite a few times in my stock 4cyl. '96 Camry. It's actually quite stable at those speeds. My favorite place to do that is on the 163 freeway down here in San Diego. I tend to drive it late at night (like 2am). There's two straight parts that are 2 miles long a piece. Great place to test what your car can do.

I tend to average about 80-85mph in my car during normal freeway driving. If you think that's fast, you should come down to San Diego and see for yourself. If you're going 75, you'll be getting passed quite a bit. I'll follow cops going 80 and occasionally even pass a cop going about 75-80.