They probably need to park in the regular lot and will be waiting for you in person holding up a sign with your name after you leave customs.
FYI:
The official airport taxis (not the rabble taxistas who bother you when you leave customs), you can book and pay with credit card at their desks before you leave customs or also outside in the public area after customs. Since you don't tip taxistas in Chile, no cash changes hands and you will pay a cheaper price than Uber.
You will need to get Chilean Pesos though as the USD is not widely accepted in Chile outside the tiny sector of the tourist industry that caters to North Americans.
(The following info applies to US issued ATM debit cards as I have heard some UK and Euro issued cards mysteriously aren't charged a Chile-side fee)
I recommend withdrawing from a BancoSecurity ATM (the only ATM that doesn't charge a Chile-side fee) or BancoEstado ATM (the only ATM that allows larger than 200000 pesos per withdraw which allows you to minimize the 4000 peso per withdraw hit) in the city.