We had a BA fly drive car from Avis last month for 3 weeks.
Picked up the car and the guy tried to pressure us into paying $9.95 a day ($208 total) for a satnav. Refused and then discovered the group of car we had booked have satnavs fitted as standard.
The guy also tried to persuade us to buy a full tank of petrol and a big sign board behind the desk said 'local gas stations charge $2.20 a gallon". Refused, got out the airport and found local gas stations charging between $1.94 and $1.99 a gallon.
Sharp practice but not really surprising.