From your picture it looks like a M2100 Meta Alarm remote/ fob see http://www.abacuscaralarms.co.uk/rem...meta-fobs.html
they say this is a replacement for the M100, which is a remote/fob for the M99T2 (and maybe M99T), in the Uk most Meta alarms fitted to Spiders/GTVs are M99T or M99T2
I've the key card won't that card have the code? - Yes it should have the code
And if so can I avoid removing the alarm EcU and recode the remote with it? don't know, but for the M99T2, the procedure is to unlock and then unlock the car with a working remote/fob 8 times (i.e. 16 presses), the red led on the dashboard will flash repeatedly and within 10 seconds press the non-working remote, it should now work!, BUT I don't know if this will work for your alarm
Is recoding the remote something very complicated? if the this is a job for a specialist who has the correct electronic equipment to 'talk' to the alarm ECU
In your experience will it be expensive? - the above company charges £105 to recode the alarm and supplies two new fobs for the M99T2 see http://abacuscaralarms.co.uk/alarmsh...d&productId=57
- I expect they wipe clean the ECU memory
Will this solution definitely fix the problem? - I guess the specialist will fix the problem
Does the master key have something to do with this process? NO the alarm system and the immobiliser system are completely separate systems. the master key is just the 1st key programmed into the immobiliser ECU/ engine ECU and is used to Program new keys into the immobiliser
Do you know why this has happened? - I don't know, the remote/fob I re-programmed into the alarm ECU last weekend was working 4 years ago
M99T/T2 alarms are located behind the radio in the centre console, I'm guess yours is also fitted there - remove the passenger or drivers carpet on the side of the console - the alarm ECU should be marked with it's model number.
Also look on the Abacasalarms website above for some guidance - or speak to them?