Rivian's website has changed a few times since I submitted my pre-order, but each time I've visited it since, including just now, I don't see how one can submit a pre-order without picking which vehicle. Perhaps you chose one and didn't realize it or maybe there is/was some path on the website that allows one to submit without picking one, but it really doesn't matter. Not sure what was (will be?) in your confirmation email but it should indicate you can easily change which vehicle you want when it comes time to place your order. Here's an excerpt from what mine said:When you say you are in for a R1T with your deposit, does that mean you know that's what you are going to configure when you can? I put a deposit down but it didn't ask me for which vehicle?
If at any time you decide you'd like to switch models, no need to cancel your order and lose your place in line — when it’s time to configure your vehicle, you’ll be able to switch between the R1T and R1S.So picking a vehicle with your pre-order is more a survey for Rivian.