Is that talking from personal experience? How many times have you tried it?
And was it just that the rental agent didn't notice the expiration date or they saw it and accepted the vouchers anyways?
I personally did it once and the agent mentioned st and I just told them confidently that it's no problem bc the rental started beforehand. Even if they happen to say anything which usually won't happen the key is to just tell them like u know.
I think it's worth the deal to be getting a premium car for $14 a day OBO!