If my short term memory serves me right, y'all are staying up at Belizian Shores? If so, a cart is a bit of a tricky thing up north. The "road" north, past the Palapa, can be a bit of a challenge from time to time. If in fact you are staying there perhaps a daily rental to explore the south end would be your best bet.
10 days is usually around $300 US, but in the spirit of competitive commerce we've been able to leverage "frequent carter points" combined with the volume that having a mob provides(3+ at a time). If in fact you are at BZS, rumor has it that the bar and pool may get a workout on Friday next. I'll apologize in advance, they don't get out of town much, and just don't behave properly in public.