Here are a couple photo's of my aftermarket internal bike rack.
I got the parts from a couple different companies.
Bottom Rail.
http://www.jensonusa.com/store/produ...ple+Track.aspx
I bought the 47" ($50) and cut it down to about 37" They have a 35" version but for some reason it's $66. You can get the mounts there for $15 each
http://www.jensonusa.com/store/produ...t+Carrier.aspx
I had, happened to buy some mounts at performance and planned to make my own rack, but then found the rail above.
http://www.performancebike.com/shop/...e.cfm?SKU=3702
I got them on sale for about $7 with another order, but they seem to be $10 right now.
Now for a road bike there are a couple issues. I'm short and ride about the smallest road bike they make and the saddle touches the roof of my X3. You might have a little more room in an X5, otherwise you'll need a quick release on the saddle. Also the bike has to go in on an angle (See photo's) otherwise the handle bars hit the hatch. I think a mountain bike or comfort bike would fit easier.
Gary