Headlights keep blowing, inconsistent issue.

I purchased this car recently. It is an unmodified D15 with a new alternator, battery and aftermarket stereo. It looks as though the wiring harness was opened up and used for the stereo and amplifier they had in it before. The car only had one headlight on when I bought it and it blew out shortly after. I replaced both bulbs [didn't touch them] and less than 48 hours later those blew out as well. When it happened the car would have what seemed like a power surge, the engine would be faster, the interior gauges all got brighter and then they blew out. After they blew out, the bright lights still worked, but they blew when I was only using them. The problems is sporadic and not related to anything I do in normal operation.

I had the alternator checked and it produced the correct amount of voltage on and off load. The fuses are all fine. The plugs are in good working condition. Any ideas?