In the 90s I had a convertible and I bought a very sleak car alarm with voice that said:
"Viper On" and "Viper Off" - I also installed a proximity sensor and it would say "Warning, you are too close to the vehicle" it was so cool. People would go at my car and say wow.
I still have the module and someone asked me if I had the installation instructions, and it just so happen that I do.
You can dowload here I am sharing.
Hope that helps.