>you can keep driving it until it gets noisy enough that you can tell better where the noise is coming from. <

Actually, it's been "noisy enough" at this point! It's getting me worried.

I started to notice the noise (rather faint then) maybe last year. Since then, Tires has been changed, alignment has been done. The noise persist. Starting this year, the noise got worse. Much worse, in a short time.

I've taken it to two shops but both times they keep telling me they heard nothing!!!