I would like to lower my 2003 C5, what is the best way to do so? Thanks!

First by looking at the bottom of your driveway and counting how many speedbumps you go over weekly! LOL

Up to an 1" maybe an 1.5" on the stock bolts. Any lower and you'll need longer rear bolts and cut the bushings up front or remove them.

Prepare for an allignement also, some guys have gotten lucky and didn't need one but most do. Also if you go over an inch you'll need some different shocks, I believe the Bilstiens have long enough travel but don't qoute me on that...

I'm sure some these guys in here have done it already and will chime in, I haven't.

Be cautious about lowering. You may hit speed bumps and other unintended objects and not see improved performance/handling. Your ride may actually suffer!

That said, my car is lowered(approx 1.5" in front slight less in back), principally because I use it 3-4/months on track(rr). I have moton coil overs which allows a good deal of adjustability and was able to corner balance the car.