Well, while it may be true that the car rental company may not always check for proof of
discount; they often do, and should. More and more, the rental agencies are requesting membership verification in order to give a discount car rental rate. That way, if the renter does not actually qualify for the lower price, they can, and will, charge the regular rate. Discounts are negotiated with organizations and should only be used by qualified members.
In my opinion, it would be better to use a discount code through a membership that you actually belong to.
Hope this helps!
Pages from this site, relating to this topic:
Finding Rental Car Coupons
Types of Discount Coupons
Free Rental Coupon Codes