Here are some tips and words of advice (based on our experiences!).
Booking car rental in your resort.
You may be tempted to leave booking a vehicle until you have arrived at your holiday destination, and then check out the local resort rental companies and hope to find a good deal. This may be a good idea, but you cannot be sure to find what you want, or even worse - there may be no vehicles available. We know this to our cost, as during our photo trips to the Canary Islands we took the ferry from Lanzarote to Fuerteventura to discover that, (after checking EVERY rental company in Corralejo, the resorts AND the Airport) that there was just not one single vehicle available for rental at all, and had to postpone our trip until the following year!
Good deals with your budget airline?
We have also taken advantage of deals with budget airlines, where car hire is offered along with the flight booking, and the car collected at the Airport when you land. This looks like a good idea until you land and discover that half the passengers on your flight have taken the same deal, and the car hire office queue stretches in front of you as your plane-load of holidaymakers through the pick-up process - we know, we spent the first 3 hours of our trip to Ibiza in such a queue, before collecting our bald-tyred, worn-clutched, gear crunching, clapped-out Fiat Punto (more of this one later...)
The 'Big Names' and 'Upgrades'.
We have also hired cars from the big 'Global' names - on our trip to Majorca we were 'upgraded' from a compact 2 door car to a seven seater people carrier! Seems like a good deal until you try to negotiate the streets of Puerto Pollenca, (through which it doesn't fit), or the hairpin bends along the northern coast, also remember that this type of vehicle has nowhere to stow away anything out of sight, neither do most modern 'hatchback' style vehicles when these are presented with the rear shelf missing!
Leaving it until the last minute?
We booked our Ibiza trip for August 2009 (peak UK Bank Holiday time) and checked various holiday car rental companies online about a month before departure - including the major names. We were amazed to see many of these had prices STARTING at £500 for the week, we left it 2 weeks then checked again. Not only did many of the companies no longer have ANY vehicles remaining, we had to pay over £700.00 for a weeks hire, and on arriving were given a clapped out Fiat Punto with a gear missing, dents, and balding tyres. We came within a whisker of having to dump this vehicle in Es Cubells as it refused to climb the road back up from the beach! On returning the vehicle to the car rental office we made the point that, at auction for sale, this old Fiat would never reach £700, the price we had been charged for a week's hire!!
Always make sure you've checked exactly what's included in the holiday car hire and whether you need to pay extras, such as child seats, air con, additional driver, sat nav and taxes. If these extras have been added and you don't need them, see if you can ditch them.
Don't ditch the child seats though, they're compulsory in Europe for under 3's, and some companies charge a whopping £60-a-week extra for these. So factor this in BEFORE you book to see who your overall cheapest is. Plus consider taking your own child seat, or even buy one once you arrive - which could be cheaper than paying the extra. Some places will add an additional cost for booking with a credit card, so look out for this hidden charge.
Reports of overcharging and claiming damages are rife. So why not take some photos of the car and make notes of its condition on the hire company's form, especially photograph any scratches or dents as these can be the prime source of dispute.
Check what the fuel policy is. Some companies charge you up with a full tank of petrol at high prices and ask you to return it empty. If you're not planning on many miles avoid these companies.
Plus if they say 'it doesn't matter whether you refill it or not' watch out. This most likely means, they will fill it up when you return it, and then charge you for the fuel at a much higher rate than you would have paid at the filling station.
Check the spare tyre is actually supplied with the vehicle, and is in good condition, also look for the jack and wheel brace - you will be glad you did if you are unlucky enough to be stuck somewhere unfamiliar with a flat tyre.
Remember that in many countries there are different legal requirements when driving, alcohol limits, seat belts, spare bulbs, warning triangles, spare fuel, reflective jackets, spare glasses, speed limits etc. Check these out before you leave, the AA and RAC in the UK have handy guides to the requirements for most countries.