I was also thinking to connect two buttons and see if single press activate one function and double press activate heater
But, I did not read of anybody experiment it, and it is a huge guess to expect that "click" two buttons of the same time is working as activate two functions, instead to be seen as an error condition by the keyfob micro processor
For 10USD you can get a 4 key key fob form ebay ... but actually .. it is not even needed
In my case I had to "patch" my ebay keyfob, since the switch I got is "taller" and once put over the red plastic button it believe the switch is pressed all the time. So I end up removing this button and using some red silicon glue for seal over the hole .. and it works perfectly now
This means it is also possible to drill a hole in the original keyfob case, and put 1 drop of silicon glue for make it looking "decent" and fully functional
I know ... one picture is 1000 words ... so I may try later to post a photo of my modified key
Possibly if I would have wait for the smaller switch this hack may not have been used ... but even if I order both types ... the tall one are the first to arrive from china and so far the only one I got
PS: This are the items I did order
http://www.ebay.com/itm/271429114081 (the tall switch, which work only with the hack above .. actualy is possible to buy only this and make a hole on the keyfob and then use 1 drop of silicon glue over the hole and switch)
http://www.ebay.com/itm/191894620615 (the 4 buttons key fob)
http://www.ebay.com/itm/361565523761 (still did not got these, but possibly these are the ideal one)
