My car is doing great but now suddenly I hear this big tuk sound from the back as if something has misplaced. It happens repeatedly with intervals. I examined my car underneath and I blame this one join which seem to be out of place. I am attaching photos. The car is Mazda 626, year 2000.

Here is a picture of the read left (the same thing) which is in place.

Can someone tell me what this is? Is the car ok to drive to mechanic (5 miles)? Can I fix it myself? How much would it cost?
