In my infinite wisdom I have lost my remote for my immobiliser and can't start my car. I have no idea what immobiliser it has as it came with the car. As i'm needing to replace everything anyway, can anyone suggest a good alarm system?

Were bouts are you located as might be able to help you out.. in the past i have installed a few differnt brands and worked for Mongoose Alarms for a number of yrs with very few faulty units its the 1 i will fit to my personal cars.. go with the Mongoose M80S which you can add microwave sensor and even a tilt sensor, window closure and even GPS tracking or paging system.. can give me a call if your in bris or between SC GC 0422750579 Danny.

Cheers Danny, much appreciated.  I'm currently in Sydney :(  
I just had a look at the Mongoose M80S and it looks the goods and there is a stockist here in Sydney that is selling it for around $450, does that sound about right?  I have a fear that it (my current set up) will run down the battery as it's been sitting still for about a week or so now. 
 
I may have to get the NRMA to tow it to my mechanics

IF it's a SW20 I think that these are an old Alpine system.
 
You should be able to get a mobile alarm installer to come out and install the new alarm to your car, or at least bypass your one so you can get it to their shop, no need to go to a mechanic.

Mr2gtracer
Cheers Danny, much appreciated.  I'm currently in Sydney :(  I just had a look at the Mongoose M80S and it looks the goods and there is a stockist here in Sydney that is selling it for around $450, does that sound about right?  I have a fear that it (my current set up) will run down the battery as it's been sitting still for about a week or so now.  I may have to get the NRMA to tow it to my mechanics

That's sounds right maybe give mongoose a call in Hornsby find out which dealers are mobile there number is 02 9482 4444 and dOnt bother with a machanic they will make a mess of it te amoun of times I use to travel out to remote locations to fix such jobs..

It is an SW20.  I forgot to mention that. I still need to get the alarm first I'm guessing.  If there is a mobile guy that can bypass it so that I can drive it to the shop it would be good.  I'm useless at electrics otherwise i would try to do it myself

Some very cool smart phone compatible tracking alarms out there now. Getting cheap too, around the $300 mark (supply your own sim card). Full control from the phone, proximity locks, remote start, active contact alarms etc. 
 
I know that's what I'll be looking at next.