Be sure to obtain unlimited mileage car rental, since distances in the USA and Canada are immense.

If you plan to fly out to one airport and back from a different airport, then check for any drop off charge for the car, which can be very high. Sometimes you can drop the car at another location within California or Florida without incurring a drop-off charge.

Also check whether driving is restricted to certain states, and whether the car can be driven into Canada if this is relevant.

It is usually cheaper to purchase any car upgrade (to a larger size than that supplied by default with a package) when you book, rather than directly with the car rental company. As well as the size of the car, you might also consider upgrading from a two door car to a four door car.

Car rental is usually much cheaper for cars hired from within the USA rather than within Canada. Rental from within Florida and California is usually much cheaper than from within the other states. It is very difficult to obtain unlimited mileage in Canada.

The car rental voucher usually only covers the basic rental cost. You must pay all the other costs locally. CDW (Collision Damage Waiver), sometimes called LDW (Loss Damage Waiver) is optional, but extremely highly recommended since it protects you from being potentially liable to the car rental company for anything up to the full value of the car, even if something happens to it which is not your fault. The cost of CDW/LDW varies from state to state, but is typically $9-$15 per day (as at summer 1996), with the cheapest CDW/LDW rates applying in California. It is sometimes possible to obtain car rental in the UK that includes CDW/LDW, in which case make certain that the rental agreement states this clearly since a considerable sum of money is involved.

You must also pay a fee directly to the car rental company for any additional drivers (typically $1 per person per day) and for the rental of child seats if needed. You must also pay them the state sales tax on the entire cost, including that which the voucher covers (at the normal rate, not what you paid for the voucher). There are also restrictions and costs involved with young drivers.

If you have "Top-Up" insurance and normal holiday insurance then the only additional insurance or insurance-type facility that you need to purchase from the car rental company is CDW/LDW, but they will try to sell you the others.

You will need to use a credit card in order to guarantee payment of the charges to the car rental company.

It is highly recommended that you take out "Top-Up" insurance in the at your departing counrty in advance. This covers your liability should you injure someone or cause property damage while driving, and it also provides you with compensation should you be involved in an incident with a non-insured or under-insured motorist. Check what level of third-party cover is provided inherently by the car rental company, since this affects the level of top-up insurance required. Recently the major car rental companies have drastically reduced this figure. Small car rental companies may provide even less cover, which could invalidate the top-up insurance.

Rental cars are full of petrol when you pick them up. Rental operators offer various options regarding petrol upon return, but the cheapest option is always to fill up yourself at a nearby gas station and return the car with a full tank.

When hiring a car from Dollar, check whether you can take it into Canada, as we have heard reports of problems. There shouldn't be any problems in this respect with Avis, Hertz or Alamo but it is always wise to check.

Almost all operators impose a restriction against their cars being driven in Mexico.

Many operators now impose a restriction against driving on unpaved roads.

Some operators impose a restriction against driving their cars in parts of New York City, especially the island of Manhattan.

A British Driving licence is sufficient to drive in the USA and Canada; you don't need an International Driving Permit.

All normal rental cars in the USA and Canada take unleaded petrol, which is universally available.

Most if not all rental cars have air conditioning (which you're very likely to need in summer) and a radio, and often a radio/cassette player.

Cruise control, central locking and electric windows are common.

Sunroofs are very rare, however.

All normal rental cars have automatic transmission, which is very easy to get used to provided you remember that when in gear the car will creep unless you keep your foot on the brake.

Since the rule of the road is to drive on the right, the driver sits on the left. However, the accelerator is still on the right and the foot brake in the middle.

Before you return a rented car be sure to sort out all the items which have doubtless collected on the back seat, in the glove box, in the door pockets and in the boot during your trip. You normally have to park the car in a queue and then collect all your luggage and remove it from the car very quickly, so it's well worth getting yourself organised in advance.