I have the DieHard Security Battery in my '85 Fiero. I like it. It works particularly well in this vehicle--if the remote trunk release is disabled, theives have to punch the lock in order to get to the battery.
One drawback is that, unlike the Optima, the DieHard has the potential to leak acid (which is why I went with an Optima for the '68), but if you used Por-15 to coat your tray or a battery mat, it should not matter.
The other drawback is the ease with which a first-gen hood can be opened from the outside. I posted a question last year
on securing the hood and got back good responses. I decided the best solution was to go with keyed hood locks like those from JC Whitney,
but I still have not been able to bring myself to drill the hood for them. Right now I'm still using a lock & chain--which is a real pain.
The DieHard and keyed hood locks should prevent a thief from hotwiring your car--won't do anything to stop external and interior vandalism though.
Just in case anyone missed it, Sears issued a recall on all its DieHard security batteries over a year ago. I think everyone who registered the battery when purchased was notified by letter.
Sears said it had received many complaints about the batteries. The one in my fiero shut the engine down and refused to restart (the starter would not even engage, but everything else electrical worked fine). Luckily, it happened when I was pulling into a gas station and not on the interstate.
[This message has been edited by cturner (edited 02-09-2003).]