I had a Z4 in 2008, loved it. Great car to drive even if you are on the taller side, I'm 6' 1" and found it very spacious even with the roof up. The rear wheel drive can be tricky in the wet or snow but so long as you drive to the conditions, you shouldn't find much issues with it in all honesty. Make sure you get the heated seats, I'm not sure if they come standard now but it was an extra when I had mine, they are great for driving around on a nice summers night with the roof down, just gives you that little bit of extra comfort I found.
When I bought my Z4, I was looking at that or the Mercedes SLK and the BMW won hands down.
Here's a couple of photos of mine, it was 15 months old when I got it. I much prefer the newer model nowadays tho.
