Really odd sound diagnosis?
 

I have an 02 IS300 with 114k miles on it, and I've rarely had any problems with it until now. I bought it used a few years ago, and it's always had a noise behind the glove box that sounds like liquid whooshing back and forth whenever I change speeds or turn. Thought it was odd, but the Lexus dealer claimed it was normal.

Now, I'm hearing really weird, non-uniform thumping noises and sounds of liquid "squirting" all behind the dash/glovebox, and I can actually feel the floorboard thumping when this happens. It's almost like a hose is banging up against the floorboard. There's nothing leaking that I can see, and this occurs at all speeds.

I initially thought this was something to do with the A/C, but it does this whether it's on or off. Any thoughts or guesses as to what this might be? I have no idea if the first thing that I mentioned has anything to do with the second, and it's a very difficult problem to describe, as I'm sure I have not done it justice. It's definitely the strangest thing I've experienced.

sounds like your blower assembly or air mix servos