central locking & music system for restored Maruti 800 STD AC 1991 model

I've restored my Maruti 800 STD AC 1991 (Type - I) model.. the work includes includes full patch job,repainting and changing most of body parts.. Now want to install Xenos central locking system with immobilizer...but a guy dealing with central locking systems qouted 3800/- for xenos FW 200-4A model and told me that  immobilizer model ie. FW 250-1A not suitable for old carburetor M800. is it true? I think going for central locking without immobilizer is worthless. So please tell me if I can get any model with immobilizer for carb m800. Please also tell me which is the good music system with NO cd player ie. only USB within 2-3K range. 

The immobilizer works through the ECM which is lacking in the carb 800, so the dealer is on the right foot.

Any other devices to function as immobilizer in carb m800? Heard about fitting a hidden switch to cut off the power supply etc. is it safe way? if yes, in which circuit and place should i fix it?

you can see this > http://www.carwale.com/Forums/ViewThread-9483.html

Its called a kill switch, and is placed on the power supply to the in-tank fuel pump, for which wires run past somewhere the passenger seat. Any experienced mechanic can fix it for a coupla hundred bucks.

Beware, though - your Maruti is old carburated one, and the fuel pumping arrangement could be different, and worse still, mechanical, where this trick won't work. Then a dual pole single throw switch cutting both ignition coils will be needed (this incidently is an alternate way to implement a kill switch).

I am wondering why are you taking so much pains on a vehicle which is going to lose its registration in 18 months time now... It will have to be protected like a prized possession from traffic cops or will have to be scrapped, so why make it up so much at the fag end of life...? I see a bit of an undertaker in you (just jokin buddy, take it cool!)

Thanks for the help. Anyway how it lose registration after 18 months? It was registered in 1991 and renewed once. Could I re-register it for another 5 yrs when it expirs in 2011?  

I guess the 15year lifespan only applies to metros.(?)