It could be a brake issue. When I bought mine it was painful to be in the car at motorway speed due to the noise coming from the rear brakes. It was impossible to pinpoint the source of the noise so I only discovered the cause after jacking up the car one side at a time and turning the wheels by hand. It was obvious at that point that it was the rear brakes.
On closer inspection, the backplates (which the handbrake shoes are mounted to) were badly rusted and swollen, causing constant contact with the discs. Took a hell of a lot of elbow grease to fix that. Wish I'd just bought new backplates... (2nd hand, not £90 each from the dealers

)
So whether it's a brake issue or a wheel bearing issue, your first port of call needs to be to jack the car up and spin/wiggle/wrestle all four wheels by hand.
<steve_earwig> I think this forum is more about keeping our cars going with minimal outlay than giving our cars more reason to go bang