Custom Ordering

I am strongly considering placing an order for a BMW330 but I'll have to custom order the vehicle for the options that I want. My question is...what is the normal procedure for paying the dealer when you custom order. Do you only put part of the price down before receipt of the vehicle or do you pay the whole amount when the auto arrives. Thanx for the info ;-).
Becky

I had to put down a $500 deposit and that was it.

Even after the car comes in, you can cancel, and they have to give your deposit back, at least in CA. It's more a gesture of good faith and a way to make sure you're serious.