Risky drive on loosened wheels

Though the exhaust pipes already welded in place, somehow the noise it created dampen my driving mood. I almost thought that the squeaking noise comes from something hitting the tail pipes even after rubbers already being placed beside the second tail pipe manifold.

After several checking, the source of the annoying noise was found. The noise was not from the exhaust piping but from the untightened bolts of rear wheels/ rims. I think the workers probably loosened the bolts of the rear wheels when fitting the new bumper but they forget to tighten it.