Welcome Trung277:
How is camping and RVing in Vietnam? Seen any tigers lately?
While I have not travelled in Vietnam, my wife's brother has lived in Laos PDR for over twenty years and he says that travel trailers are not common there. I know, I know - completely different country, but...
Are you thinking of importing an Escape travel trailer to your country - might be expensive! Might be better off getting one of those righthand drive 4X4 camperized vans that are popular in Japan.
If you visit Canada or the western United States you may wish to try western style RV camping with the amazing Escape Trailer. We don't have the same wildlife issues here, but you may see the odd rattlesnake, bear (black or grizzly, depending on location), cougar (kinda like a tiger but no stripes), or skunk. The Escape travel trailer offers adequate protection from all but the latter mammal.
Thank you for your introduction - its nice to hear from overseas camping/RV enthusiasts.
cheers,
G