The main factor to consider here is the age (18 years) of the vehicle and its components, especially rubber suspension parts and hard-working ball bearings. Luxury car manufacturers design very complex suspension systems for NVH isolation (noise, vibration, harshness in engineering terms) and for ride quality and handling. These systems do tend to be "high maintenance" on vehicles like Lexus, Mercedes, BMW. Having an "Alignment Inspection" performed by an undercar expert can reveal all the potential problems and enable you to prioritize your repair expenses.
Jim O'Neill - Chino Autotech Inc., Auto Club SoCal AAR
SAE Int'l SoCal Section Board of Governors,
Vice Chair, Service Technology Programs
NASTF Service Information/Communications Committees
Auto Value/Bumper-To-Bumper CSC Nat'l Council
ASE CMAT-L1, CA. Smog Check Technician
AMI AAM Accredited Automotive Manager