Identify a car-hire center. As India has developed over the past few years, the demand for hire cars has increased, prompting a number of hire centers to crop up around the city. Most are located by the airport (north of the city) for when people arrive.
Set things straight with your driver. Indian roads are chaotic. It's common to see vehicles going the wrong way up the highway, several people crammed on a motorcycle and people making daring runs across roads. And because of this, virtually all car-hire companies will provide you with a driver. Mumbai is huge, and it can be a nightmare to park at popular places of interest, so having someone who can park the car for you and meet you after you've had a walk makes life a lot easier. It also means you're not liable for any scratches or bumps. However, drivers can be pushy and may be keen to make some extra money by visiting their friends' hotels or restaurants. Immediately show that you have your own agenda and won't be pushed into anything.
Take the necessary paperwork. If you decide not to have a driver, you'll need an International Driving Permit. A deposit of about 10 times the car's daily charge will also be expected
Make an advanced reservation. if you've just landed after a long flight and are suffering from jet lag, the last thing you want to do is have to find a hire center. You can easily find them online and make a booking. However, don't be afraid to pick up the phone and call them directly to negotiate a price, particularly if you need the car for a couple of days. Some companies have relationships with specific airlines, so that might also lower the price. Not all drivers will speak English, so it's worthwhile mentioning this when booking. At the very least, have a pen and paper handy to write down where you want to get to.
Research service levels. Regulation in India is fairly low, so it's not uncommon to find varying levels of service between companies -- what you see is not always what you get. Search through forums or travel guides for information about specific companies.
