i dunno about 96 but i think 95' and up xls most of them came with alarm, if not all.
I have a leather xls and has remote (from factory I guess) since i was able to program my very cheap (actually cheapest on ebay I could find) remote from the park/brake module in the trunk.
A friend of mine just bought a 97 xls, non leather, but that does have the alarm I believe , since it has the security light up by the outside temp/ clock. I did not check if it was under his seat or in the back but...
My range really sucks, you have to be next to the car but....at least i do not put the key in..... however it could be my 15$ remote or the batteries in it.
This was the one i got (about a year ago) and I had to email him to send me different programming instructions then the stock ones that he shipped to me or found online (meaning what and which buttons to press before programming it)
http://www.ebay.com/itm/TOYOTA-KEY-K...ht_2101wt_1185