Yes, I have had several of the calibre units installed in cars I had prior to my Gallardo. I did not have the Laser Diffusors though, so I can't comment on their effectiveness.

When the Calibre is installed properly it's really steathly and a pretty good radar with few false alarms. It's very classy. I did have a problem with a defective k40 and the bluetooth sensors not syncing to the brain. That required another trip for the component to be replaced.

Some things to think about before you make your decision:

No matter how good your radar is when your on a back road you can still get nailed and K40 DID NOT pay my ticket when I got nailed doubling the speed limit like they advertise.

I do not know if the range is as good on the k40 since the sensors are down so low. I just use a hardwired V1 under my mirror in the Gallardo. It seems like the V1 has better range being higher in the car. Except it looks like a piece of junk and has too many false alarms. It is only really good on the highway.

There really isn't much research out there on the K40, which is pretty frustrating. I hope I helped in some way.