The most frustrating experience I have being passed while speeding is on Wise Road (a curvy, two lane road in the forest with no shoulders leading into Rock Creek Park) in Washington, DC. It is a short road feeding into the park with a 25 mph speed limit and the last 1/3 mile is down hill so I usually cruise down at 30 mph. Especially during rush hour, I get passed and the worst part is that there is a stop sign just ahead with 2-4 cars backed up so they aren't going far anyway.
About speeding, I don't really care and I feel good that at least I am not polluting the park on my ride home.