Hey, sounds like you're having a bit of a nightmare there. Not too long ago, I was having a similar issue with my 2003 Kia Optima. The alarm kept going off unusually, even when I was driving. And my battery? Pretty much identical to what you described. Turns out, the alarm system was indeed at fault. The system was coded to activate optical locking, and it was causing unusual activations and battery drainage. My garage guy had to reprogram the alarm system. It's a bit of a technical fix, and not exactly your everyday problem. Think it happens with age, you know, like most of us, these systems tend to have their little glitches over time. Hopefully, this helps you out a bit and you can get your car sorted without any more drama. Good luck!

Hey there, thanks for the quick response! Glad to hear I'm not alone with this sort of problem - it sounds like our cars are behaving almost identically. You mentioned your mechanic reprogrammed the alarm system. Do you happen to remember how much that set you back? And has anything else come up since the fix? Would really appreciate any additional info. Cheers!

Hey, no worries! Always happy to help a fellow car enthusiast out. Fixing the alarm wasn't a huge deal for my wallet, the mechanic charged me around 45 Euro for the reprogramming job. Not bad, yeah? And to your other question, everything's been peachy since the fix. No more unusual midnight serenades from the alarm, or grim moments with a weak battery at startup. The anti-theft system operation has been smooth - guess sorting out that optical locking glitch did the trick. So, for your Kia Magentis, I reckon you might be after a very similar solution. Good luck with it, hope this info is helpful! Cheers!

Ace, that's just the information I needed! I appreciate your insights and also relieved to hear that the fix wasn't too costly. Fingers crossed, I'm hoping my visit to the mechanic will go just as smoothly as yours did. I'll definitely bring up your solution and see if a reprogramming of the alarm system is what my Kia needs. Really appreciate it, dude! Cheers!