yea thats fine. I heard of others who had one letter. You should ask the dealer to fax/email (pdf) a copy of the GM Workbench (this is the order form). It will have the six digit number up top, and it will also tell you what "priority" you are in the lineup of orders.
I believe you will have to pay additional (I think $495.00) for the polished wheels. I am not 100% sure of the cost. When I ordered it was not available yet. I am waiting until after SEMA to change my order one more time, after I see what goodies from SEMA are available. Good Luck.
When you go to your dealer, be PREPARED. Know what you want and what EACH item costs. Knowledge is key here. Before placing your order, you must know an agreed upon price. That means they say MSRP, $500 below MSRP, etc, etc. and you come to an agreement. Then, you place your order with your salesman. Already knowing what you wanted, you should be able to price your car EXACTLY to what the dealer comes up with.
Depending on dealer, they might as for a deposit. This SHOULD be in form of a check. The dealer SHOULD keep that check and NOT deposit it. The check MUST be fully refundable in the event something unforseeable happens. Do not accept that they must now go and find another buyer and this takes time, etc. if you have to back out on your order. Someone will snatch that car up like hotcakes if you don't buy it. Also, this check will be put towards the downpayment on the car...make sure that happens.
Then, you are set. Sit back and wait until you are notified by the dealer that your Camaro order has been pulled. The dealer will call you when your order has been built and delivered. Go in knowing that your car, built to your specifications, will be ready to go at the already agreed upon price that you already had them put down on paper.
When you go in to buy, pay them however you will. Shop for the best APR before going in to the dealer. The dealer will probably be able to give you the best APR available. BUT, always check with your regular banker to see if they can beat or match the price. Whom you go with is up to you. Fill out the financing paperwork and sign on all the dotted lines. You will pay state tax, title, and license upon completion of the sale. It'd be wise to figure that out before going into the dealer as well.....those surprises aren't fun.
DO NOT accept any other dealer added charges to the sale. That "paint sealant" stuff is NOT something I will EVER accept (as a car is built to factory specs and the paint is just fine). If there was something wrong with the way they painted the car at the factory, they'd fix it. Do NOT agree to ever pay for sealant (just my opinion...). Some dealers might charge a 1.5% advertising fee. That's for you and your dealer to discuss. I've been told all dealers are assesed this fee. There might be other fees that a dealer tries to add in. Your best bet is to take someone with you who has done this before. Look over EVERYTHING and ask EVERY question that you can. If you don't ask, you will never know and might end up paying for something that you weren't expecting.