You would generally have to go to the DMV and pay sales tax and register the car yourself if you bought it in Texas, but if you lease, Tesla is the one doing business with US Bank (the lessor), so Tesla collects sales tax from you, forwards it to US Bank, and then US Bank pays the state of Texas, because they actually own the car.
I ordered 2/23/15, vehicle was delivered 4/23/15. I had: $5000 CCR + $150 TR + $700 AF + $1300 FMLP + $6450 ST - $2500 DP = $11,100 due at signing. Tesla had the registration and plates ready about a month later, I took the vehicle in to have license plates installed (I had them put the front one on, I didn't want to risk a ticket), had them install the 2nd charger, and a few other items.
The on-board chargers are a somewhat confusing issue because I don't think Telsa explains it very well. Here's the explanation in a nutshell:
To charge the battery, you need DC power. But, the commonly available power at any wall outlet is AC. So somehow, we need to convert AC to DC. The car's on-board charger (or chargers) do this. The car comes with a single charger that can convert up to 40A of AC power to DC. There is an option to add a 2nd charger, which allows it to convert up to double that (80A) of AC power to DC, so the charging times can get cut in half. But, to take advantage of this, the AC power source (the outlet or EV charger) must also be capable of greater than 40A, otherwise the 2nd charger wouldn't be used.
The typical AC power source that can do greater than 40A is the Tesla High Power Wall Connector (HPWC). It can be wired to deliver up to 80A. Some public chargers (with the J1772 connector) can also do more than 40A, but they're not that common.
Now, note that this applies only to AC power sources. If you use a DC power source, like a Tesla SuperCharger or DC Fast Charger (with Chademo adapter), this does not apply. Those types of chargers do the AC to DC conversion before the power gets to the car, so the on-board chargers aren't used or needed.
So, to sum up, when does the 2nd charger result in faster charging?
1. When using an AC power source to charge, AND
2. When that power source itself is capable of >40A
I have an 80A HPWC in my garage, so for fastest charging, I opted for the 2nd on-board charger.
By the way, if you're not driving the car for business purposes, you might really take a strong look at buying the car instead of leasing. Buying the car gets you the $7500 federal tax credit, which you can't get with the lease, and on top of that, Tesla's lease terms are not real good as far as leases go. The capital cost reduction amount is fairly high, and the residual value (amount you'd pay if you want to buy the car at the end of the lease) is probably going to be a bad deal if you want to buy the car at the end of the lease.
I only leased because I can come out ahead with the business tax deductions.