I just ordered a 35i... scheduled for completion on the 18th

So I have a few hobbies that sometimes require trips to Home Depot to get wood and stuff. I'd really like to be able to pull a trailer to carry a few things. I see that BMW has a 2" hitch accessory available... but my dealer wants $1100 for it - $500 for the hitch, $600 for install. So I was wondering if anyone has put their own in. I'm wondering if I could save myself the $600.

Sam.