WTK: Alarm/Pager/Keyless Entry...

I want to know what the difficulties are, if there are any on aftermarket keyless entries systems as oppose to an OEM or dealer installed system.

This is a part of the car, that I'm afraid to go to a Chop shop like Al & Ed's.

I know there was an article the showed how to connect an aftermarket Alarm system to the Vacuum Pump for the MBZ's.

Any recommendations of particular brands...? for some reason European cars to me have always been synonymous with ALPINE. But I just found out that they stop making Security Systems.

Any particular install shop's or dealerships...? There was Henry's back in my day here in Orange County, which later spawned of to Audio Chamber, and I think it's the whole thing that start Al & Ed's Autosound...

I'm really not into 1-button remotes, I like the new LCD pager alarms.

Thanks for any advice.

-J