I bought my car brand new. It used to be so tight in the handling, now I have

Sit ups! .

New steering and suspension parts are probably needed. With 125K on the odometer, I would say that they are past due. Do the front and rear at the same time, and take a look at polyurethane anti-sway bar bushings as a cheap upgrade. Cheaper to fix and keep her. ;-)

I felt the same a couple weeks ago. Felt like I was driving the Flintstones car! BUSHINGS!! My front left control arm bushing was pretty mangled. So much so that it was firing up that DSC malfunction. This had been going on for over a year. But no one ever "noticed" it when I took it for wheel alignments, tires, etc. $100 later my car is just like it was at 14,500 miles. Now it has 150,000. :)))) 2001 Z3 3.0i