As a rule, staying downtown, rental cars for Fest are not economical. Call the Radisson to check, but downtown hotels typically charge $20-30/day for parking. Add $20 for onsite parking at Fest or $10-20 offsite, plus the cost of the rental, wll, it adds up pretty fast. If you drink enough beers to make that pay (beers at Fest sell for $3), then you may not be in shape for the drive back. There's no re-entry at Fest. So if you park off-site, you can't get back to your car. But if you park on the grounds, they collect your tickets when you enter the lot, so you can return to your car and then go back into the Fest. That parking is $20 and fills fast; plan to be in line by 10 a.m. weekdays, earlier on weekends. If you don't rent a car, taxis to Fest are $4/person each way, or the meter rate (about $10 from the Radisson) plus tip. There's a city bus that you can get at Canal & Basin for $1.25 that goes to Fest. Or if the streetcar really is running, including the Carrollton branch, you can ride that to Fest for (I think) $1.50. If you do decide to rent a car anyway, check downtown rates. There's a Budget across the street from your hotel (location code MY3). By not renting at the airport, you may save as much as 40% off the airport rates, which could more than make up for the cab/shuttle ride to get from the airport. And you can usually still return at the airport when you leave, no extra fees.