Here's the completed install of a Whistler Cruisader on my '05 F4i. It was a ***** getting it in, but well worth it! I don't think any LEO would even notice it. Suprisingly, the blue LED at the top of the dash is quite visible, and the "heads up display" works quite well. If anyone is trying to install one, PM me and I can save you a lot of time and frustration.
The way I finally got it in was I drilled out the holes on the black metal straps that came with it so the mounting screws on the back of the display would fit. I bolted the display to the straps and cut it so there was only one hole left. I attached this hole to the underside of the Key lock bolt.
The radar head fit nicely inside the fairing at the very bottom. I attached it with 2 sided sticky tape. I attached the remote laser sensor on the undersurface of the front fairing with 2 sided tape as well.
I've just attached the blue LED to the top of the cluster with black electrical tape. If anyone knows a better way, please let me know.
I will update this post with my impressions of the unit's functionality as I use it more.
you can see the blue led taped on the top of the instrument cluster