When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
No. D2S and D2R are not sizes. They are Type of bulbs. D2R for reflector. and D2S for projector. HID's come in all different size for almost every signle car. only one that does not have an HID kit is H3. SOME company makeHID for H3 but it doesn't work to well. reason being a H3 bulb filiment is perpendiclar to the bulb which means the light come stragiht forward instead of to the side like ALL other halogen bulb.(i attached a pic of H3).
4100k is going to be the brightest and a bit yellowish at times
6000k is most popular but not as bright as 4100k but more blue and looks more nice
8000k don't bother.
main concern should be brand name though. go for hella, or phillips if you can