@Anonymous
IMHO join as soon as you can and start building a relationship with them. If your portfolio supports a new credit card, maybe app for one of their cards and put some spend on it monthly and PIF before the statement cuts. At this point, you would have at least a three month relationship with them prior to apping for the auto loan, and that can never hurt. They truly are (again IMHO) the best CU in the country and your late grandpa's military affiliation will open the door for membership. Don't worry about getting any of his military ID before you join, just call and they will ask you for his basic info. If you are applying for a credit card when you open your membership, the underwriting is the same for all except the Flagship. The FS has a $5K minimum CL but you may find that would be a good 2nd Navy card to pick up in the spring when they usually offer a $500 SUB for a minimum spend. This time of year you can't go wrong with any of the other cards (Cash Rewards, More Rewards Amex and Platinum). If you already have a great rewards card, Platinum is nice because it is their lowest interest card which is great for BT's. Never any BT fees at Navy on their cards is a nice bonus as well. Let us know what you decide to do!! 
@Anonymous wrote:I went into a Tesla showroom this morning to test drive the performance. I ended up ordering one there on the spot. I set up delivery to be around December and the guy said they'll call me around that time to confirm that's when I'll want delivery and I can push back if wanted. He said once I set up a delivery date is when I should go around to shop for a loan and get the best rate and just have the offer ready on delivery day. I'm so excited and I know these next few months are going to drag lol
Haha! That's the problem with Teslas, especially the Model 3 Performance. Once you test drive one, you can't resist ordering the car! In the first half-mile, the Performance blows away anything on the road including supercars like Lamborghinis and Ferraris! (For a lot less money..)
@Anonymous gave you some good advice regarding your loan. NFCU may well be your best bet. I wouldn't hesitate to open an account with them now and apply for a credit card if your credit portfolio supports that. I got my Tesla loan through Navy and they were terrific to deal with.
Regarding insurance, each of us has such different insurance requirements and profile that you cannot say one company is better than others for everyone. In my case, I saved about $400 per year by insuring my Tesla with the company's captive insurance company rather than State Farm, which insures my home and other cars. What I like about Tesla Insurance is that they take advantage of the cars' high-tech and telematics to cut insurance premiums for Tesla buyers. For another buyer, however, a company like Progressive might work better. YMMV (literally) because there are so many factors involved (e.g., age, driving history, credit history, number of cars, etc).
@Anonymous I'm with @ridgebackpilot and say apply for the card if your current profile supports it. Navy will pull TU for the new card app and EQ for the car loan (I'll say YMMV because they can always change it up but that has been the norm).
@ridgebackpilot I can't wait to drive my bro's car when I'm on the mainland. He has the Pro package as well and said it's like a rocket. Nice insurance savings by going with Tesla's insurance! That $400 a year you save buys a lot of gas..oh wait..you don't need it lol!! Now I'm really jealous!! 
@Anonymous wrote:@ridgebackpilot I can't wait to drive my bro's car when I'm on the mainland. He has the Pro package as well and said it's like a rocket. Nice insurance savings by going with Tesla's insurance! That $400 a year you save buys a lot of gas..oh wait..you don't need it lol!! Now I'm really jealous!!
@Anonymous Be careful driving a Tesla! It could be a very expensive test-drive! Even my Model 3 Long Range AWD performs like a rocket. I can't imagine what the Performance model is like. Having that much power wasn't quite worth the extra $5K-$8K to me. But because it's a Tesla, I can always buy a performance upgrade for $2K that allows me to launch even faster!
They are expensive cars but very cool technology and very safe if you read the manual... Many states have such great rebates that the car helps pay for itself. I installed a 240 volt charger in my garage so that I can charge at 40 amps, nearly as much as the car will take. I can fully charge the car from empty in about six hours. My electric company (PGE) offered me a special electric vehicle rate so I can charge from midnight to 3 pm at about half the nomal rate. Superchargers are much faster, of course, and even they are far less expensive than buying gasoline!
Driving a Tesla feels like you're driving into the future. My other cars now feel like they're mired in the past with their outdated internal combustion engines!
@Anonymous wrote:@ridgebackpilot @Anonymous
I just recently handled all of the negatives on my credit report that were there from the past few years. I currently only have one card open that I opened to help rebuild my credit. The limit is only $500 and I only have $20 max on there each month. My FICO 8 from experian is a 637. Do you think it would be worth it to open up a card with Navy Federal or just wait until I apply for my auto loan in December?
Good job beginning to rebuild your credit. However, the answer to your question--and whether you can qualify for a loan to buy an expensive car--depends on a lot of factors, not just your credit score. For starters, what's your annual income and debt-to-income ratio? Is your credit file thin or thick? Do you have a mortgage, other car loans, other revolving loans?
If you need another credit card, applying for one with Navy Federal is a good idea as they tend to give high limits to people who are rebuilding or have relatively thin files. It certainly wouldn't hurt to establish a good lending relationship with Navy Federal before you apply for an auto loan. But that alone won't guarantee your loan approval. They will look at all the factors I mentioned above.
There's a reason you generally see older people with nice cars. They're usually the ones who can afford them and can get approved for loans to buy them! Of course, each person's credit file is different and YMMV. Good luck!