Like erdoran said, that split the rebate talk is BS. You should call him on that and ask to see the paperwork. Look at the other threads mentioned. You should be getting much more than $10K off MSRP. If he won't do $10K off MSRP tell him "no thanks, and good luck moving that car. Maybe you could sell it if you didn't just flat out lie to people."
ED July 2016 - One of the last e89 Z4s to roll off the line
35i Estoril Blue / Beige Kansas Leather, M Sport, Premium Sound
CWP, Technology Package, PDC