Sport/Navi Packages and Options

[Jason]

I just test drove a 370Z Base Auto. I absolutely love the car and will be buying one soon. I have a question about the factory packages and options. I have always been hesitant to add options to cars I've purchased because (1) I don't like to finance optional equipment and (2) I can usually find the parts cheaper through a dealer or online after purchasing the car. My question is, is this the case with the Sport/Navi Packages? I would think I could buy the sills, mudguards, etc. later on from the dealer. But is it a better deal getting the Sport package now or just buying the parts online (brakes, wheels, spoiler). Is that possible?

Thanks in advance and I look forward to being on the boards more often once I take delivery of my Z.