 when i got this car it was awesome. then all of a sudden going about 30 mph car would shake and my mileage decreased from combined city and highway 25 to 19 mph. i repeatedly took it in and nothing wrong was found. although dealership felt the shaking right away. they couldnt fix it. repeatedly took it in.all of a sudden a service bulliten came out that this is the way the car is supposed to drive.b s. i say. i contacted nissan usa and tried to reason with them. and they told me yea thats the way it is. i am a car audio installer for more than 8 yrs, and i have worked on many nissan altimas like mine. they all drove great.. obviously there is something wrong. i trade piece o crap in.