Bulbs and ballast all depend on your budget. You can spend $50 or $250 on components. I'm an OEM type guy so I run Lexus D2S Denso slims ballast that are potted for weather. Currently running some Morimoto XB in 5000K since I had them laying around when I bought a Morimoto HID kit to play with and use as testing.I agree, the DRL's look great on the '15's. However, I've got numerous other visual mods that I plan to do, so I'm less motivated to spend $400 for nicer looking headlights. Mostly I say that because I'm going to be adding rally lights to the grill like the previous gen Mustang GT.
Good to know about the foreground limiter, thanks for sharing.
Do you have a recommendation of which bulbs and ballast to use? Did you also get the high beam splitter and wiring harness? Thanks!
If I have to buy new bulbs, I would go with Sylvania CBIs, which are affordable these days at around $110/set. These have been the king of the hill for years until Sylvania released their CBH and CBB models. I have a 9005 high beam splitter, it was like $5 when I was already ordering stuff from TRS. You can find in eBay for a few bucks if you want to wait 3 weeks for china shipping.