Car Alarms: DEI viper car alarm, viper car alarm, replacement remotes

Question
I recently purchased a car with an alarm system.I am told its a Viper alarm,but the key fob says "DEI" RPN471T 266  rolling codes  FCCID EZSDEI471. I never had an alarm system.I have no idea how to use this system.Sometimes the alarm works and sometimes it doesnt( I beleive it is user error)Is ther any way to get free instructions, or will I have to pay for them? Thank-you in advance.
                    Tim

Answer
I don't deal with DEI products, but you do
seem to have a system of they'res. Try
www.DIRECTED.com (VIPER)  or  www.remotesunlimited.com
(specializing in replacement remotes)
to see if you can get more information/manual for
it.

Good hunting.

ALARMTEK