Hi S & J
Bad news is that they are not preinstalled - rather, they have been offered as a purchasable option by Abril28, a subsiduary of Grupo Masa, for 725 euros for the living room, and 685 euros for each bedroom, and this Company will complete the installation, at the above cost (+ 16% i.v.a.). These prices are given for villas with pre-installed air - conditioning ducts.
Pre-installation tubes are now standard on all villas except M14 and M15.
Villas without the preinstallations will cost 925 euros for the lounge, and 885 euros for each bedroom, the tubes being only slitely visable, as they would be covered. Once again, + i.v.a. at 16%.
Stangely, these prices would appear to be reasonable, by Masa standards, having looked at local newspapers, when we were down there last September 06.
I would suggest that, if you are interested, to contact your agent and ask for details, I believe that Abril28 have a time limit for the installations.