Just picked up a car not too long ago and I figure I do a tune up since I will be keeping the car. I have a 2011 328i xDrive coupe A/T. I'm looking to buy genuine spark plugs and ignition coils.
For the sparkplugs I found that "12-12-0-037-663" Is the part number. I'm still unsure so I would love if someone could help me verify. I can't determine the part number for the ignition coils. Does BMW
make their own ignition coils? Or do they all use Bosch coils.

Love to help but I'm not at my work computer currently. Honestly the absolute easiest thing to do is call the dealer parts department. Have your vin handy, and ask for plugs and coils. When they give you the quote ask if you can have the part number.

Also, on the coils, ive gotten them in bmw boxes but you pull them out and they're Bosch. But they flip flop over the years.

Make sure yours isnt one of the years with the specialty socket for the spark plugs.

plugs - LZRF6AP11GS NGK
Coil - 0221504800 Bosch

Theyre the same as original

This! the Ngk number maybe smaller depending on if you buy them from a parts store but most of the time the plugs can be same heat range+ core type and be fine

i used to work for bmw.
the first two numbers of the part number is the category.
like what this guy said, if the guy isn't an asshole or if you get unlucky and happen to call when the parts manager is taking calls they wont give you the part number
for the sole purpose of losing a sale.
but most of the guys usually dont mind giving you a full part number
just have VIN on hand. they will usually tell you they cannot look up a part under year/make/model, they will demand the VIN.