I have now fitted an after market keyless entry system to my 2003 Spacestar, and my experience may or may not help others;

The Spacestar, post 2002 Model year, only had central locking from the driver's door keylock, previous models having it from both front doors. This can be a hassle, and a keyless system is obviously a great help. The dealer solution is based on charging around £180 for a Cobra system, which is reliable, but I think the fobs are terrible. A Cobra system bought separately is about £70, sometimes less.

You DO NOT need another actuator/ motor to get the Spacestar system to work, ignore the websites that say this is the case. The Spacestar works from a door lock ECU, that requires a switch signal to earth. If it sees this, it locks or unlocks all the doors, simple as that.

All the aftermarket systems seem to use two miniature relays as their basis, one to lock, one to unlock. The system is based on two sets of three wires from these relays, using the common and normally open connections. one goes to earth, and the other goes to the appropriate wire on the back of the ECU connector, and the remaining normally closed wire is cut off. The unit requires a permanent live feed and an earth. There are usually other wires from the unit for indicator lamps, which is optional, and also global closing / boot release, which are not required / possible for the Spacestar.

There are a few kits out there including Cobra, Falcon Phaser and Rightclick. I have tried a Rightclick kit, and I think you get a reasonable unit, but with a slightly cheap fob. Doing this again, I would go for the Falcon kit for a better fob. Instructions for many kits seem minimal, and as I said before, they recommend another motor for driver's only door sytems, and that just isn't needed.

If you want any particular details, please ask via this forum.