In the order agreement updated 3/18/2019 it says:
Order Process; Changes. After you submit your completed order and the options you selected become available in production, we will begin the process of matching your order to a vehicle and coordinating your Vehicle delivery. Your Order Payment covers the cost of these activities and other processing costs and is not a deposit for the Vehicle. Until your Vehicle is delivered to you, you may cancel your order at any time, in which case you will receive a full refund of your Order Payment. Until your order is matched to a vehicle, you may make changes to your Vehicle Configuration.
https://www.tesla.com/assets/pdf/model3_order_agreement_en_US.pdf
I believe it used to say something like this?
"Your Order Payment is fully refundable only until your order is matched to a Vehicle, at which point it becomes nonrefundable"
Order Process; Changes. After you submit your completed order and the options you selected become available in production, we will begin the process of matching your order to a vehicle and coordinating your Vehicle delivery. Your Order Payment covers the cost of these activities and other processing costs and is not a deposit for the Vehicle. Until your Vehicle is delivered to you, you may cancel your order at any time, in which case you will receive a full refund of your Order Payment. Until your order is matched to a vehicle, you may make changes to your Vehicle Configuration.
https://www.tesla.com/assets/pdf/model3_order_agreement_en_US.pdf
I believe it used to say something like this?
"Your Order Payment is fully refundable only until your order is matched to a Vehicle, at which point it becomes nonrefundable"