I just hit 39k miles and finally getting around to doing the 30K service. I've always done mobil 1 for oil but in talking with a friend he says he puts synthetic everything in the car. The service person said it wasn't worth it. Probably because they were planning on topping off rather than doing the actual flush and fill job.
So - question is:
Is it worth it? Assuming the answer is yes, what are the brands, part numbers, etc... I need to go and get it myself at a retail store.