Thrifty - Do I need to be a blue chip member to receive airline miles?

I have a month-long rental coming up and want to receive 1500 miles (of course). Do I need to be a blue chip member or do I just tell them the airline program at the rental counter?

No need to be a Blue Chip member. Either give it to the agent at the time of rental or put it in when you book the reservation. Just make sure it's in there before you return the car--once that happens, no guarantees you'll get the mileage...