Didn't even think about renting a car in Goa in April. Hiring a driver for an 8-hour day was never more than 1000 Rs. ($21 US). [I also always bought the driver lunch, which apparently was not expected.]

Anyplace you are staying in Goa should be happy to arrange a driver to collect you at the airport. If for any reason this cannot be arranged, there will be taxis waiting at the airport.

Taxis will work for all-day or from town-to-town. Within towns you will use autorickshaws, which are usually called "autos" or sometimes "tuk-tuks."

I was there for the parade of saints and relics in Old Goa and this was a spectacular sight. I'd recommend a visit to Old Goa in any case. For an excellent guide seek out the tall, skinny fellow outside of the cathedral. I'm really sorry I can't recall his name. He's a Hindu with a physical disability, extremely knowledgeable about everything and unlike some guides with prepared speeches quite happy to answer your questions and adjust a tour to your specific interests.

If travelling to Old Goa from Panjim enjoy lunch or dinner at the Star Bar en route. This was an excellent "authentic" experience with great food in huge portions, al fresco with ore freighters chugging by.

You're going to have a great time. I wish I was going back.