Funny/weird story.

We were out of town for the long weekend and were driving on some wet, muddy gravel roads. By the time we headed home on paved highways we noticed a high speed vibration.

We stopped at a service station and checked the tire pressure and the tires themselves. Nothing apparent. Guessed it might be the alignment or balancing thrown out of whack because of driving on rough roads but it seemed like a stretch.

After the dealer had a look at it we were told that the buildup of crud and rocks in our stock rims was enough to cause this.

Yet another reason to keep the car clean. We will most likely avoid gravel roads as much as possible from now on.