Help needed: check polarity of light bulb sockets for a potential LED Kit

Cross-post from 996 turbo forum: Could someone please check the polarity with a voltmeter in the bulb sockets? I'm assisting a vendor in potentially assembling a full led exterior bulb kit for the 996 and I don't have a multimeter. This is important for the operation of the bulbs; is the positive pole (+12V) on the center tabs (bottom) of the bulb, or the bulb socket ring tab (sides)? This is especially interesting on the double filament rear brake/tail bulbs, but also for the rest of the bulbs to make sure we get the right ones. Maybe some one know just knows the answer from experience or a prior repair and won't have to buy/dig out a multimeter. Please let me know what model and year your 996 is if you post. Thank you!

Typically the barrel is ground and the pins are +, but I do not know if Porsche follows the standard. Here's a bayonet socket diagram for a single filament bulb: Bayonet sockets with two contacts for single-filament bulbs do not follow this "standard:" Bayonet sockets for dual-filament lamps also have a grounded barrel with the pins both designated +: Multimeters are cheap...I really do encourage you to get one unless you wind up absolutely convinced the Internet gives you the correct answer.

Having recently worked with these 'less than superior' made in Poland bulb sockets and lamp harnesses I can confirm the center posts are positive and the bases are ground on my '02 996. I'm sure you know this, but be certain to include an electronic flasher with your bulb kit or you'll be forced to deal with resistors which are a real hassle.

Thank you for the thoughtful replies. Yes its going to be a total package including all exterior bulbs and led compatible flasher. If its a success the vendor will post it here. And I'm going to get a multi-meter.