My Lexus RX 350, 2007 has very old headlights(the light looks yellowish).

Is it possible to replace them and make the lights look like modern car lights - whitish color (I guess it’s called xenon lights)?

If yes, should I replace only bulb or entire headlight should be replaced?

 

If possible restore your headlights then apply clear film to prevent yellowing again. If they are too far gone next best option is a good used set. Failing that, look at aftermarket.* I assume you have halogen if so this LED bulb will make a great upgrade
https://auxbeam.com/collections/led-...a-h11-gd002120

If you have Xenon then replacements are going to be expensive even for used. * a word on aftermarket headlights, whenever possible I try to use CAPA certified this means insurance companies deem them just as good as original when it comes to light output. Not all non CAPA certified parts are bad, but some are. Example: I put a CAPA certified Depo set into a Highlander they fit just like OEM and the light output was the same.

 

Yeah the current bulbs are halogen ones.
If replacing with LED bulbs, should I replace low beam, high beam and daytime running lamp?

 

DRL is part of the high beam, at least in Canada this means replacing the high beam with LED won't work with this possible exception.
https://www.morimotohid.com/morimoto...s_3?quantity=1

 

I replaced my halogen lights on my 350 with HID assemblies from an RX330. Do note that you won't have the auto-leveling feature if you do the conversion as the linkages and wiring are not present to support it, but the bulb itself is plug & play if you also get the beige housing cover on the back that has the wiring attached to it

 

If you have reflector housing headlights (not projector) do not put LED bulbs in them. The beam will be all over the place and actually worse than with the stock halogen bulbs. If I were you, I'd do what MattRX did and replace the halogen reflector headlights with the HID assemblies, new/aftermarket or used. The xenon stuff is expensive, however.