You can get several pins with or without wires from your Audi dealer. Search for pins here in the forum and you will find several topics. One of Ted's topics lists parts number and where those pins are used.
They are usually crimped as soldering may not be at reliable as crimping is. However, without the right tools it's a pain to crimp the pins right. I would probably try crimping first, and solder as well if it doesn't look as solid as it should be.