What does the man say he did?

M Okay, your vehicle is ready to go. We changed the oil and examined your brakes. The brakes look fine. W Really? That surprises me. They’ve been squealing so much, especially in the city. And every time I’m on the freeway, if I put on the brakes the car seems to rattle, really shake around a lot in the back.
M Well, I drove the car around the block and applied the brakes several times, and I didn’t hear a single squeal. As for the rattling, have you considered there might be something in your trunk that’s causing the rattle?
W Oh no, I didn’t even think about that. Now that you mention it, I have parts of a bed frame back there. I’ll take it out and see if the car continues to shake. But that still doesn’t explain the squealing.