2003 Galant Key w/ chip 03

what ever u buy for your car will work fine if properly installed.  if u buy a remote starter or alarm or remote starter & alarm combo, they'll all work.  if hooked up right, u can put your original car remote on the shelf wih peace of mind & the one purchased with the new addon system will do it all if hooked up by the intaller.  sensors might be added to the new brains u buy, they are not hooked upto the vehicle directly, sure they are mounted on the vehicle, but they are hooked upto the new brains electrically & the new brains looks after them.  the stock remote will still work like it did before, and it won't control the new brains u buy & it never can.  the new remote of the new brains will do what is does and it'll have the functionallity of the factory remote as well, if hooked up by the installer.  go visit & talk with a few dealers before u set down your $.