On servicing, if you don't use a main dealer and there is a grey area type problem of any kind, you may not get any goodwill from the manufacturer. The value of the goodwill could be quite substantial. I suspect, with Lexus, that goodwill gestures are quite common because of their high JD Power rating. Perhaps with some other manufacturers goodwill gestures are few and far between. In those cases I wouldn't go dealer servicing.
On OEM items, it staggers me how long original Japanese bulbs last. As soon as you have to replace one with a reputable make at a car spares place they seem to last about 2 years max.