Recently, I experienced difficulty starting my '99 V70. The car has 84K miles and never had any starting irregularities until this time. Here are the details: The car started normally and then died immediately. It would then crank normally but would not start after 4 or 5 attempts. I took the key out of the ignition and went to look under the hood (yeah, like there's anything you can really do under there). When I got back in and tried it again, it started right up and has been fine for a week now. Could this possibly be a symptom of an impending immobilizer antenna failure? Has anyone replaced this part themselves?
Any info or advice would be appeciated.

had the same issue with my 1998 S70 , dealer said bad antenna ring ( causes the key not to connect to the ring , making the car beliving its being stolen)

my problem went away when i changed my car battery , has been fine for over a year now....

// ermik

have same problem, finally cut another key and hide it inside. If this problem
shows up change keys. Also I have read that keep all the metal garbage off the key this messes up the reception from the transducer inside the key. Anyway there is a way to bypass the immobilizer.
good luck,