Hello everyone. I own a 1999 range rover 4.6hse. It now has 92,000 miles and it's still a pleasure to drive. I need some help diagnosing a problem that no one has been able to fix. Not even the dealer's mechanics. Anyway, I need to find out why at highway speeds of 60mph-75mph, does my car vibrate at the front end. I have changed my tires, speed balanced them, and i have recently rotated them. What else should I check or change? I appreciate anyone's advice. Thank you