Q : We just got back from Puerto Vallarta. Interesting fact: Banks, money exchange places and resorts were not willing to cash American Express Travelers Cheques. What’s up with that?

A: Traveler’s checks are no longer welcome in many countries. Many shops in Europe stopped accepting them years ago, and I don’t get them when I travel. You often have to go to banks to get them cashed, and that’s a hassle. And then there are fees. I do hear that they are still welcome in China.

—Carol Sottili

Q: I’m flying United next month. When I made my reservations, I selected exit-row seats, and the site said that I had “successfully selected” my chosen seats. After I entered my credit card information, however, my seat assignments changed. I called United and asked about the seat assignments; they say that exit rows are under airport control and they are not assigned until people get on the plane. I’ve selected exit-row seats before; any idea what’s up?

A: Often, you are unable to reserve the exit-row seats until you arrive at the airport, although some airlines now sell those seats for a premium. If you show up early and ask for the exit-row seat, you should be able to get it. (Also, please bear in mind that United is still consolidating its reservations system with Continental, and many glitches are being reported.)

—Christopher Elliott

Q: We got a package to Riviera Maya (six adults) for the end of February and are looking for reliable options for getting to the area of Akumal. I’ve seen many transfer operators, but it’s difficult to decide. Also, are there any recommended tours to Chichen Itza? Unfortunately, we will not be able to rent a car. We would like to be in a small group and try to avoid the stops at “gift stores.”

A: As you’ve figured out, lots of shuttle services are available between Cancun and Akumal. Go to the airport site for choices. It should cost about $135 each way for the six of you. I’ve taken shuttles and taxis from Cancun to various resorts south of there and never had a problem. As for going to Chichen Itza, I would rent a private taxi van driver. With your group, that shouldn’t be too expensive. Ask at the hotel for a recommendation. I would avoid tours. They take forever, and I’m with you about the stops at the gift stores. Plus it will cost just as much.

Q: We are going to rent a car at the Paris airport and spend three full days and two nights in Normandy in June. Our main focus is the WWII beaches, and musts are stops for a couple of hours each in Giverny and Chartres. Any tips on how much time we need at the beaches (Is one full day enough? Should we hire a guide?) and other stops if we have time (perhaps Rouen, Honfleur, Mont St. Michel)? Should we stay in Caen or Bayeux?

A: By all means go to Mont St. Michel. As for the beaches, yes, I would hire a guide. D-Day Historian comes highly recommended by a friend, and you do need at least one full day to see the beaches. So arrive the night before and plan to spend the next night there as well. Bayeux is a lovely small town and a good place to base yourself, as many tours of the beaches leave from there.

—Zofia Smardz

Q: Heading to Vieques, Puerto Rico, in February and looking for ideas on what to do, aside from luxuriate on the beach. Any cool outdoorsy things?

A: The scuba diving. I will never forget the incredible drift dive I did there a few years ago. And check out Bio Bay

—Carol Sottili

(Puerto Mosquito), which is best seen at night.

—Christopher Elliott

Q: Any tips on steps to make sure you’re protected while renting a car in Mexico? Are there certain companies with better or worse reputations? Is this one instance where I should take the insurance?

A: Mexico often requires additional insurance of U. S. drivers, even when you are covered by car insurance or your card. I would definitely stick with the brand names when renting there. That way, if something goes wrong, you have a place to complain to (and that will respond).

—Christopher Elliott

Q: For our first wedding anniversary, my husband and I will be driving from Santa Fe, N. M., to the Grand Canyon. We have about a week, and are looking for any must-see sights, hotels or restaurants on our route.

A: You’ll be passing right by El Malpais National Monument, Petrified Forest National Park and Canyon Diablo, all worth your time, I’d think. Flagstaff, too.

—Joe Yonan

Adapted from the Washingtonpost.com Flight Crew chat conducted weekly by the Travel staff of the Washington Post.