In the last couple of days I noticed a noise that gets faster or slower depending how fast I'm driving. It's hard to describe the noise, but something like two empty baked bean cans scraping each other. I've been putting very heavy weights in the car recently such as boxes of large heavy porcelain tiles, and countless trips to the rubbish tip with stacks of bags of heavy rubble and wood from house clearance whilst my place has had builders in. It's a peugeot 307. When loading the car with these things, the rear of the car was weighed down and I could see it lowered quite a bit almost going over the rear wheels. The noise sounds like it's coming from the rear offside wheel. Could it be bearings or CV joint?