Car rental in san juan

Hi!

We are headed to San Juan for a 2 day pre cruise rest! We have 4 small children and are interested in seeing other parts of the island. Would you recommend renting a van, chartering a tour (not really interested in that!) , or taking a cab?

We live in a large city and are pretty adventerous and have experienced the wildest driving in the world...China! So not much will surprise us on the roads.

Any tips would be great!

Claudia