1. Plan the entire trip around the temperature/seasons in Mexico & Central America

Camping on Mexico's Yucatan Peninsula in May and June is oppressively hot

2. Bring a lap-top

It allows you to enjoy your campsite while writing instead of a being couped up in a stuffy internet cafe

3. Add $5,000 to your budget

We had saved $25,000 but dropped an unanticipated $3,000 the first week when our van broke down in Newport, Oregon

4. Bring country-specific guidebooks that have maps of individual cities

The Rough Guide to Central America has very few city maps, which makes for stressful driving when first arriving in a new destination

Tie

5. Study Spanish as soon as possible

The Escuela Mexicana in Guanajuato, Mexico is a great school to do it at.

5. Have a tight fitting mosquito screen for van side sliding door

Somehow this obvious one had escaped us until we were at the tip of the Baja. We ended up ordering one from Go Westy Campers in Los Osos, California and having it shipped, at great expense, down to La Paz on the Baja.