Alamo, like most rental car companies, charges .50 per day if you choose to earn frequent flyer miles from most airlines. The exceptions are
Air Canada, American and Northwest. For these airlines, you pay a small "tax" which is 5% of something (I forget what).
Unlike several other companies, I am unable to put my frequent flyer number into a Quicksilver profile, so you should show the appropriate frequent flyer card at the counter for each rental and hope they enter it correctly.
As sosafan says, Alamo charges for the miles. What they don't do is tell you. I noticed my bill was $4 more than the quote, the guy looks at it for a while, then spots the charge. It is not that obvious on the itemized bill either. I have no problem with this (other than I think it is dumb and drives away business) if it is posted and/or told when asking. The issue was the not informing.
oops. forgot to add my ffm number to a rental last month..is there any way I can still get the miles?
If you paid a frequent flyer daily fee, or a Frequent Flyer Tax Recoupment Surcharge, you should be able to get your miles. If not, you would need
to modify the contract and expense. I would doubt that you could do it,
but you could always ask.