I bought a used certified Honda accord 04 EX L automatic it has 62000 miles on it. before i bought it during the test drive it was shaking when the sales man used the AC so the next day he said they fixed it and i did another test drive and ac didnt make the car shake or vibrate so i bought it. any ways driving it 100miles later it does the same thing but not as bad its a noticeable shake/vibration so when i went to the dealer ship to pick up my extra keys i asked them about it and the guy(mechanic) said that it is normal for a honda accord with 62000 miles to have minor shake or vibration and told me to just buy gas from shell and he said they tighten up the ac pump or something to tone down the shaking/vibration. it still shakes should i go to another dealer and have them take a look at it im in los angeles. anyways i know that i have 30days from purchase for them to cover anything that is wrong with the car. any advice thank you for your time if this question has been answered before please link thank you verymuch