Viper Alarm and Valet remote?

Not the same exact thing but I have a DEI Sidewinder 7000HF and a Code Alarm CSI400.  I was told since they are both stand alone units, they would NOT be able to work with one remote so I said "screw U" and tried it anyway (hate it when people tell me I can't do stuff).  So what I found out was that the DEI is at freq 434 while the code alarm was at 433.  The Code Alarm was not able to learn the DEI remote HOWEVER the DEI was able to learn the Code Alarm remote.  So now I use the Code Alarm remote to run both DEI and Code Alarm  units.  Still have yet to go back to the store and show off at "what could not be done".