I wanted to see if I could beat 140, which I've heard is the cap for a stock sonic, I did a couple runs back and forth across a stretch of interstate from one exit to the next to verify it was free of debris or les flic, waited for all cars to pass by so I'd have a nice clear run... but by the time I hit 125 there were taillights coming at me fast and I went with the better part of valor.
I need a closed track, trying to find my own is tricky.
I do love onramps though, I get to go from zero to a bit past local speed limit as fast as I possibly can, I can be completely sure there's nobody in my way, and it isn't even illegal (well the bit past part, but that's a law nobody, cops included, observes)
Good luck finding a track where you can hit top speed. At a local track I could only get to about 100 mph on the straight away. Would be fun to go faster though!