The length of C5W light bulbs in B6?

[WeekendDriver]

Hello,

I want to replace some lights (mostly interior) with LEDs. So, I go to ETKA to find out what kinds of light bulbs go where. Turns out that some bulbs are V3W, T4W and V5W, no problem with those. But some are C5W:

For instance, N0177252.

Once I started looking up those, I found out they come in at least 5 different lengths, from 34 or 36 mm to 42 mm. How can I find out which ones I need?
Are all the bulbs of this type the same throughout the car (e. g. reading lights and license plate lights)?

[egovreau]

A couple of the parts houses (USP and ECS) sell LED lighting kits which should have everything you'll need. At least for the interior. Not sure about bulbs for the license plate.

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