You will need a panhard rod regardless of weather you lower the car or not.
If you lower the car you will need a shorter panhard rod.
Buy an adjustable one, then if you change the ride height again you can adjust it accordingly.
you dont really need it but its a good idea, just be prepared for a little tyre scraping when the car is loaded up. as when car is lowered the rear axle becomes a little skewed. panhard rod just fixes that up.
i had my car lowered 35mm and had no panhard rod i just got some tyre scrapage on edge of tyre if the car was heavily loaded up.
"You will need a panhard rod regardless of weather you lower the car or not. <BR><BR>If you lower the car you will need a shorter panhard rod. <BR>Buy an adjustable one, then if you change the ride height again you can adjust it accordingly.