Hey what is the best place to mount HID ballasts? (Assuming the car did not come with HID's) Car is a 2004 Cooper S. In addition, what is the maximum thickness for the ballast in order to not smash it against anything when closing the hood. Also, 35w or 55w?

Thanks ahead of time for the help.

 

I would get a thin as possible and mount it on the bottom of the headlight just like the OEM xenon.

 

I believe 35w ballasts are significantly more reliable. I had issue after issue with my 55w from TRS, but they kept sending me new ones every year when the old one crapped out. Good customer service, mediocre product. I'd stick with 35w as the output difference wasn't noticeable to me.