NU Car rentals Chicago (yes new kid on the block) have set a low rate so they may get you to the door of only office they have all over in the world. But that doesn't make them any humble. Once in office here's what you should expect from rude staff:
a. The deposit amount is $500 even for credit card booking. Which is unheard of. No other rental company blocks more than $200 deposit.
b. The liability insurance is compulsory - so about $13/day is additional.
c. For other insurance coverage like damage waiver etc. you have to have insurance details of your company else you pay.
So it was like this fees, that fees, add - add - add and add.
Putting it all here so others don't get ripped by them.