It is normal for the dash lights to stay on for a couple of minutes after removing the key. Do they go out after you lock the car? I'd maybe sit around for 3-5 minutes to see if they go out. If not and they stay on and that's the reason your battery is draining you might be onto the right path as one of the most common electrical items to fail on some of the older Porsches is the ignition switch. Typically with a bad ignition switch you will see systems of the car refusing to start some of the time, the key may not turn too easily in the ignition, or strange electrical problems may appear. Be sure to check out our ignition switch tech article
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