Z4 Coupe Si or SE Spec Differences

[dasherdiablo1]

Hi guys & girls,

Well having had a good long test drive yesterday I've now decided I am definitely in search of a good affordable Z4 Coupe. I've seen quite a few advertised all of various trim /model. What are the differences between the SE & Si versions? Are there any must have options?

If anyone hears or sees a good car could they email me to let me know.

Thanks