Yes! All of the rates we quote include all of the taxes and fees.
Note that this price includes taxes and fees that everyone has to pay--things like airport concession fees, energy surcharges, licensing fees, state/city sales taxes, and other similar things. It doesn't, however, include charges for insurance products like Loss Damage Waiver or Supplemental Liability Insurance and other products like upgrades, refueling options, roadside assistance coverage, additional driver charges and other options. Depending on the country you're renting in and what kind of coverage you have, you may need to purchase coverage from the rental company at an additional cost. (For US residents who carry a car insurance policy and rent in the US, coverage is optional and can be declined.) But if you decline those optional extras, your total at the rental counter will be the same as your confirmed total price. If your price is different when you pick up your car, be sure to review your rental contract to make sure you haven't inadvertently agreed to one of these optional extras.
Many rental companies let you view your reservation on their own websites, even if you book through a third party. If you do, you can usually see a detailed price breakdown of each of the specific rate items, including each of the taxes and fees. It may even be helpful to print this out and bring it with you when you pick up your car so you can make sure everything matches up.
Note that very rarely, a government entity, airport authority, or rental company may add a new tax or fee after you make your reservation but before you pick up the car. When this happens, it's usually because the airport has decided to build a new car rental facility or city residents have passed an initiative adding or increasing car rental taxes. Since these taxes apply to everyone equally regardless of where or when the rental was booked, they wouldn't fall under our price guarantee. This is very rare, though--it's only happened a small handful of times in the last decade, so you shouldn't worry about it happening to you.