The 00-03 manual transmission Honda Insights have the tendency to heavily "buck" while driving. My dealer and I tried just about everything a few years ago, but couldn't fix it. In the end, they told me there was no problem. I've been driving around the past few years with my EGR valve blocked off with a plate of steel which has fixed the problem completely.

The only issue now is getting the car inspected. Blocking the valve off causes an error code and the engine light to turn on. Before getting my car inspected, I have to take the plate out and pull one of the leads to the 12V battery to reset the computer. Then drive around until the light turns off, and get it inspected. The shaking/bucking returns until the plate is put back in.

DISCLAIMER: it is a violation of federal law to tamper with your emission system, so this procedure is illegal in the US.