I don't know how to best explain this I will try:
Almost everytime I wash the car and I also throw water under the car (inside of wheels and axes), when I then try to move the car, usually backwards, I feel that it is having difficulty to move as if it was tight somewhere. With more pressure it then moves suddenly but after a very heavy sound on the rear axe, as if something has broken or something was blocking the movement of the axe and suddenly broke.

This only happens after I wash the bottom side of the car. I hope you understand my BAD description

 

Sounds like your brake pads are temporarily sticking to the rotors or your parking brake is binding a bit.

 

Your parking brake is binding the pads to the rotors. I wouldn't worry about it!

I have this washing the car too (or sitting in cold/wet weather for a while w/ the parking brake engaged).

It seems to be worse in cold weather, but I had this happen in the summer as well.

The manual actually warns against using the parking brake in freezing temperatures, but that's gotta be worse.

 

Hey fellas, unless you park at an incline, leaving the tranny on 1st or reverse is another alternative to using the e-brake.

 

This piece of information may or may not be relevant to you.

Another situation in which grinding can be heard is when placing the transmission into reverse from a stopped position, e.g., when leaving a parking space. Grinding occurs here in part because reverse is often not a synchromesh gear. If one does not leave the transmission in reverse or a forward gear when parked, it is likely that s/he will hear grinding in the transmission when shifting into reverse no matter how far the clutch pedal is held in when shifting. To avoid grinding in reverse, one must "clear the gate": first place the gear shift into a forward gear, then shift into reverse. This will eliminate any grinding that is heard. It works because all gears have the same speed when the car is stopped. - from Wikipedia

 

It sounds very reasonable. Thanks to all of you.

 

Or just hold the clutch in and wait long enough (5 seconds at most) for the transmission to stop spinning,...

 

Happens to me too in the mornings usually.....just the pads and rotors breaking up (but staying friends)