problems with mazda 3.. what to do

[matt]

My passenger side suspension makes some grinding crunchy sound when going over a speedbump. It's only the passenger side that does this. Upon visual inspection, the struts and springs look fine and the car itself drives fine.If I book an appointment with Mazda, they will most likely tell me the car is fine and ding me $100 for diagnostic. Should I take it to an independent dealer to have it looked at and replace the components if neccessary? I don't mind spending the money if it gets fixed. I just have an issue with someone telling me nothing is wrong and charging a fee (when obviously there is a problem)I also have this rattle underneath the trunk area. I suspect it may be coming from underneath the car.Something from the front headlight assembly area is also making this very loud high pitched buzz.. It get's louder every month..The car is still under warranty it's 11 months old 2011 mazda 3 with 45,000km.When cruising on 5th gear (auto tranny) as I apply acceleration, I can feel a slight knock from the transmission. It started happening recently too. It doesnt happen in any other gear. I tried it using the fake manual modetake it to the dealer? or take it to a small reputable shop?