[DenverSteve]

Look at and rub your tires. You should be able to verify the cupping or other uneven tire-wear situation. Since you've been advised twice that it's a tire issue, I would start there. Front end noises, on a rear-wheel-drive vehicle can only be the few already suggested issues. You'll have to eliminate one at a time. The high-performance tire shop you took it to should know what they're talking about.