Hello and welcome to EM Howard.
Lotus is developing a variable compression ratio engine. See here:
http://ecomodder.com/forum/showthrea...ase-11392.html
Also, I believe Saab was working on one a while back. Haven't heard anything on it recently.
Also also, I believe Volvo has a electronically controlled hot/cold air mixing valve on some of their engines. I don't know Volvo stuff well at all, but I've heard someone here mention that they have them. Hopefully someone else can elaborate.
Interesting idea and we here have promoted warm air intakes for quite some time here. A lot of us don't mind loosing power, so the mixing valve isn't even necessary.