Prius (2004-09) :: Excessive Wind Noise On Highway And Mild Clunk When Engine Kicks On

I'm loving this 'new' 2004 prius with 177k miles on it that i just bought. In New England winters I'm still getting 40-45 mpg and I'm not even trying to get great MPG's.

1.) Wind noise : My biggest disappointment is excessive wind noise over 55 mph. I 'm using this car as a taxi and its so loud inside I'm a little embarrassed with customers in the car. It sounds to me that its coming from the passenger window or passenger side near the windshield, but I can not identify its location at all. I've always been the one driving when looking for it though.

I called a dealer that sells lots of gen II used prius's and he says its fairly common to replace the window seals? The car has a clean car fax.

2.) Mild clunk when the engine kicks on. Not all the time, but sometimes : Other thing is, I can sometimes feel and hear a mild clunk when the engine kicks on. I also feel a little bit if vibration when the engine is on and i'm idling (it was 16 degrees last night so the engine stays on for heat). The oil level is good. I'm due for change in the next 500 miles.

Is this anything I should be concerned about? I'm sure I'm just overly sensitive.