After receiving this mail for the 3rd time, I checked it out on Hoax-Slayer: 

Sad, especially if you are inclined to 'help' people...
While driving on a rural end of the roadway on Thursday morning, I saw an infant car seat on the side of the road with a blanket draped over it. For whatever reason, I did not stop, even though I had all kinds of thoughts running through my head. But when I got to my destination, I called the Police and they were going to check it out. But, this is what the Police advised even before they went out there to check....

Outline
Warning message claims that criminals in the UK are placing infant car seats containing fake babies on the sides of rural roads as a means of tricking potential victims into stopping their cars so that gang members can rape and rob them as part of a gang initiation.

Brief Analysis
The supposed warning has no basis in fact and should not be forwarded. It is not an official police warning as suggested in the message. This supposed police warning is nothing more than a UK variant of a hoax message that has previously circulated in the United States, Canada and elsewhere.

 To read more about this and other hoaxes, check out the Hoax-Slayer website: http://www.hoax-slayer.com/infant-car-seat-gang-warning.shtml