So, today I went to an alignment shop that was recommended by a very good friend and experienced car/airplane mechanic. The owner of the shop verified that yes indeed this car had been lowered on all four corners, using aftermarket lowering springs. There were Bilstein shocks on the rear and two dif...

So it was indeed the front wheel bearing hubs that were making all that horrendous noise. Had a good quality suspension/alignment shop positively identify the issue, and order/replace the bearing hubs. I'm rather unhappy with the total parts and labor cost (over a grand), but the car drives normally...

My newly installed home-made mesh grille with Volvo logo badge. I may or may not add the diagonal slash later.