2004 BMW Z4 - Same size rims?

Are the rims the same size front and rear?

I don’t know as I can’t see the wheels from here . Why do you ask ?

Not enough information to tell. BMW Z4’s had the same size wheel (rim) front and rear for some option levels and different sizes for other option levels.

A way you can tell all by yourself. Go out to your car. Find the tire size on the front tire. The size should look something like this… 225/40/18 on the front and 255/35/18 on the rear. If the tire sizes are not the same, the wheels aren’t either.

OR you could find the sticker on the door jamb or on the glove box door that tells you how much air pressure should be used to inflate your tires. That sticker will also tell you the proper tire size for your car and if the front and rear are different, your wheels (rims) are different sizes, too.