Keyless entry on non keyless car?

[RiceeatingSHO]

Could I buy this:
http://cgi.ebay.com/ebaymotors/TAURUS-SHO-KEYLESS-ENTRY-KEYPAD-MODULE-89-90-91_W0QQitemZ150277806364QQcmdZViewItem?hash=item150277806364&_trkparms=39%3A1%7C65%3A10&_trksid=p4506.c0.m245.l1318

Plug it up and get key fobs to work with it? It can't be that simple but i know relatively nothing about this stuff.

 

[Kens1992mtxSHO]

I don't think that one will work as the 1990 models didn't have the keyless entry. I don't think that was offered as an option until 1993.