Yes, we have driven to Belize, as part of an Adventure Caravan tour.
We drove from the Yucatan Penninsula in Mexico to Belize and Guatemala.
It was an interesting trip - would not like to do it alone though.
English is spoken there and signs are also in English - this helps with the navigation. Roads were acceptable and we stayed in a very nice c.g.
but I do not remember the name.
One thing you have to pay particular attention to is having proper insurance for your vehicle. Also there are special stipulations for taking a pet into the country - and you WILL get ripped off with stupid charges at the border.
Would we do it again - probably under the right circumstances. It was a real adventure!