Complete all major repairs and scheduled maintenance before you go. Has your engine light been on for a while? Does your oil need changing? Most major problems start out small, so it's better to fix any issues now instead of calling a tow truck on the side of the highway in the summer heat.
Check your glove box! Do you have all necessary insurance and registration papers in one place? Are they current? Hopefully, you won't need them, but it's better to know where things are than to be scrambling for something later.
Clean out your car! It's a great time to get rid of stuff you won't need on the trip. Take out heavy winter equipment--will you really need snow chains in July? You already have enough to pack, don't add unnecessary weight which will add to your fuel cost.
Don't risk your paint job--schedule a complete wash and detail after you return to remove all the bugs and dirt.
Fill your tank! You know where the best prices are at home, so get it done before you go. Looking for the best price on the road? Try http://gasbuddy.com to find the lowest prices on gas around the nation. Map it out! Getting lost is no fun on a road trip. If you're tired of the interstate, try America's back roads. You;ll have less traffic, plus you'll see some sights you never dreamed could exist. Use www.roadtripamerica.com and www.roadsideamerica.com to plan an unforgettable adventure.