UrQ grinding and crackling noises, and electrical smell upon boost

[nde264 at lulu.it.northwestern.edu]

Last week I checked out an UrQ for sale in the area.

A few issues that I noted:

1)  There is a grinding/rattling noise coming from the rear of the car when it
is moving, it goes away when stopped.  It sounds kind of like a diesel engine.
Rear diff?  Wheel bearing?  It doesn't get louder or higher in pitch as speed
increases though, just goes away when stopped.

2)  With the car running and when moving or not, there is a crackling noise
coming from under the drivers front speaker.  What could cause this, it didn't
go away when I turned off the fan, though it sounds like the fan is stirring up
some debris or something.

3)  While test driving on the highway, when I floored the accelerator and the
turbo built boost, an electrical burning smell entered the cabin.  This only
happened once.  I tried to replicate the problem to no avail.

The car seems to be very well sorted, and I'd like to buy it, but I need to
resolve these issues before I buy.

Any input?

TIA,

Nathan Engelbert
89 90q