Dumb question, probably but...
 

I thought I would ask anyway. I bought a 2013 Nissan 370Z with sports package but I have heard much good things about the Navigation system in the touring model. I like the looks of it as well.

In any case, I am not a DIY person and am seeking recommendations about getting a good system (both purchase and install). There is a local Best Buy here but I have no idea whether there are good systems for the 370Z, whether they look nice and work well and whether tyhey could be trusted to do a good install.

Any suggestions?

The kenwood double din radios are pretty nice and have Garmin GPS. As far as speakers for the door just listen to a few and see what fits in your price range but make sure you get an amp for them and the bigger the amp the better. Makes sure you get a component speaker with a separate tweeter. As far as subs go I doubt best buy will have anything that is made for our cars. There are some enclosures that they will have that will be generic but still work but there are some other vendors on this site that make enclosures for our car.

At this time, I am not sure I will be getting speakers and subs and such. Just a navigation system and blue tooth. I wonder what the price is for these.

A double din head unit upgrade in your base + sports is a great alternative to the $7K or so that OEM navigation costs in the Z. You can spend anywhere from $400-$1500 on an aftermarket head unit depending on whether you get an older model (still BNIB) or the latest and greatest. Installation should run a couple hundred depending.

I would find an audio specialist in your area rather than buy something that might not be what you want in the limited Best Buy selection. Check the audio shop's pricing if they purchase and install, and ask for a separate price for install only. Price the HU online (Crutchfield is a good start) and compare to see which route is best for you - it's easy to order it online and bring it into the shop. Do your research and know what HU you want ahead of time based on features and reviews.