I recently replaced my rear bushing on my 04 cts-v w/77,000miles, 2 days later my "Service Vehicle Soon" message came on my screen. I checked all the fluids and everything is good. No DTC codes came up either. could it be i need to change my axle fluid level? Any ideas on what else i should check? I need to figure this out before the wknd, as she is going to the track!