Bottom out rear end

I have a 2006 Mazda 6. The leftrear side bottoms out on simple bumps. The tire seems to scrape the wheel well. Changed the shocks but still have the problem. The mechanic could not find anything else wrong. Someone please help.Could it be a bad spring but it doesn’t look broken to the mechanic. Please help.

You need a second opinion, the shock certainly sounds like the best guess, if the spring appears intact, we are back to the shock absorber. A second opinion hopefully will reveal the problem.

Put the car on a frame lift, remove the left rear tire, and carefully inspect things including that spring that “looks good”…A broken spring can drop down on itself and hide the break…A missing snubber or travel limiter will allow tire to body contact…

I have the same problem but with the right back tire. i have replaced the springs and shocks. Just wondering if you found out what was wrong…thanks.

Caddyman is onto something here. There should be a rubber component that stops the axle from bounching up so high that the tire rubs on the wheel well.
A spring does not have to be broken to fail if it has lost its memory (made from cheep materials or with a defective process), but the lost snubber is most likely.