Strange sounds from front and rear:

All those sounds are consistent with normal operational sounds (at least for a Prius ) and they come from the engine compartment in the front.

The whirring sound is the pump which moves hot radiator fluid to and from the thermos type bottle . . . and you are correct, it is to warm up the engine quicker.

The hissing followed by the clicking sound is the brake accumulator.

Welcome to PriusChat berinker.

 

Hi Bud,

There are three "system main relays" located within the traction battery metal enclosure at the back of the car. Maybe you are hearing the relays engage and disengage...

 

I knew the Prius made strange sounds, but since I've only had mine for three weeks, I'm still getting used to them. Last week I actually climbed up into the attic over the garage, determined to locate what must me a giant bee hive. After a thorough search with a flashlight, lots of sneezing from insulation, and a few times nearly missing the beams and going through the garage ceiling, I realized it was the Prius.

 

the clinking and rattling in the back might just be the spare tire or the metal tools used to change the tires... double check to make sure they're securely fastened... if not, then it might be the relays like Patrick has mentioned.

 

Did you get both an Owner's Manual and a Scheduled Maintenance Guide with the car? If not, buy them, either from a Toyota dealer or online. They can answer questions like that one and save you trouble and money.