OK.. I'll jump on board..
89 300 SEL I'll give it an 8, something about the front doors squeaks on rough roads, but on most roads, it's pretty quiet.
92 Park Ave Ultra W/ 200K still gets a 10.. Solid as a rock, a little wind noise above 80, but not bad..
88 Jeep Wagoneer (Cherokee) well it's a Jeep.. It's noisy, it rattles, and squeeks, it's lifted SOME.. But at highway speed, the tires, and stereo drown out all other noises.
And since it's been totaled once, and I have no money in it, and it's WAY dependable, I'll give it a 5...