I bought a new '08 a few weeks back as a commuter car. Long story short there is a vibration sound when driving the car. We took it back once thinking it was just a tire out of balance but that's not it. The car does not pull like it is out of alignment either, just a vibrating thumping type sound when traveling. It finally stops or is just not audible due to additional road noise after 55 mph. I'm thinking it the tires, they are Goodyear tires.

Anyone else experiencing this?

 

hmmm i just bought my 08 si
and i had that similar sound just not to long ago when i downshift to slow down.

 

Mine is constant from take off to like I said around 55. The best analogy would be like a bubble on the tires. Very annoying.

 

I have a 07 LX and have the same problem. But mine is usually when I hit bump or just imperfections in the road to vibrate mine.