I did a search on the previously posted link. (Thanks for the info). From what I can tell, it is legally required to have a carseat in the taxi. (I'm sure someone will correct me if I'm wrong). Here is a link to the verbage that I've pasted below:
http://www.leg.state.fl.us/Statutes/index.cfm?App_mode=Display_Statute&Search_String=&URL=CH0316/SEC613.HTM&Title=->2001->CH0316->Section%20613
Title XXIII
MOTOR VEHICLES Chapter 316
STATE UNIFORM TRAFFIC CONTROL View Entire Chapter
316.613 Child restraint requirements.--
(1)(a) Every operator of a motor vehicle as defined herein, while transporting a child in a motor vehicle operated on the roadways, streets, or highways of this state, shall, if the child is 5 years of age or younger, provide for protection of the child by properly using a crash-tested, federally approved child restraint device. For children aged through 3 years, such restraint device must be a separate carrier or a vehicle manufacturer's integrated child seat. For children aged 4 through 5 years, a separate carrier, an integrated child seat, or a seat belt may be used.
(b) The Division of Motor Vehicles shall provide notice of the requirement for child restraint devices, which notice shall accompany the delivery of each motor vehicle license tag.
(2) As used in this section, the term "motor vehicle" means a motor vehicle as defined in s. 316.003 that is operated on the roadways, streets, and highways of the state. The term does not include:
(a) A school bus as defined in s. 316.003(45).
(b) A bus used for the transportation of persons for compensation, other than a bus regularly used to transport children to or from school, as defined in s. 316.615(1)(b), or in conjunction with school activities.
(c) A farm tractor or implement of husbandry.
(d) A truck of net weight of more than 5,000 pounds.
(e) A motorcycle, moped, or bicycle.
(3) The failure to provide and use a child passenger restraint shall not be considered comparative negligence, nor shall such failure be admissible as evidence in the trial of any civil action with regard to negligence.
(4) It is the legislative intent that all state, county, and local law enforcement agencies, and safety councils, in recognition of the problems with child death and injury from unrestrained occupancy in motor vehicles, conduct a continuing safety and public awareness campaign as to the magnitude of the problem.
(5) Any person who violates the provisions of this section commits a moving violation, punishable as provided in chapter 318 and shall have 3 points assessed against his or her driver's license as set forth in s. 322.27. In lieu of the penalty specified in s. 318.18 and the assessment of points, a person who violates the provisions of this section may elect, with the court's approval, to participate in a child restraint safety program approved by the chief judge of the circuit in which the violation occurs, and upon completing such program, the penalty specified in chapter 318 and associated costs may be waived at the court's discretion and the assessment of points shall be waived. The child restraint safety program must use a course approved by the Department of Highway Safety and Motor Vehicles, and the fee for the course must bear a reasonable relationship to the cost of providing the course.
History.--s. 1, ch. 82-58; s. 1, ch. 86-49; s. 2, ch. 87-200; s. 2, ch. 91-136; s. 28, ch. 94-306; s. 903, ch. 95-148; s. 35, ch. 96-350; s. 56, ch. 99-8; s. 240, ch. 99-248; s. 1, ch. 99-316; s. 18, ch. 2000-313; s. 40, ch. 2005-164.
It looks like this was updated in 2005, so it may have changed. From what I am reading, it looks like it is required unless you are on a school bus, bus for hire, tractor, motorcycle, large truck.
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However, as a parent of two little ones, I understand that it is a pain to lug the carseats. I justify it by imagining how horrible it would be if an accident happened during our vacation and how terrible it would be to live with the consequences. My husband, however, thinks I am nuts! For short trips, I do use a low back booster for my 5 year old and the Safety First Tote N Go (folds really small) for my 20 month old. Here is a link to the Tote N Go:
http://shop.store.yahoo.com/perfectlysafe/travelvest.html
Just a warning that the Tote N Go is a fairly horrible carseat. I had to practice and practice installing it at home so that I would be able to install it correctly in a taxi. But it is relatively small and better than nothing for a young child.
Honestly, good luck on your trip and I am totally not trying to flame anyone at all!
Jennifer