This figure is several times higher than the 16 percent who favor South Korea and the 11 percent stuck on Japan, according to Cho Tot Xe, a popular car listing website in Vietnam.
Ho Chi Minh City residents prefer newer, more expensive vehicles compared to those in Hanoi, the website's data shows.
HCMC buyers favor used models released in the previous three years at a cost of VND300-700 million ($12,900-30,200). The top three models are Hyundai Grand i10 2016, Mazda CX 5 2017 and Honda City 2016.
But buyers in Hanoi are more interested in vehicles priced less at VND300-400 million ($12,900-17,200), which date back to 2015, such as the Toyota Vios 2015, Hyundai Grand i10 2015 and Kia Morning 2015.
The demand for used cars is on the up, listings on Cho Tot Xe rising 22 percent from 2018 to 200,000 last year, with the most popular brands Toyota, Kia and Hyundai.
Sedans were the most popular used car types in 2019, with Honda City 2016, Toyota Vios 2017 and Mazda 3 2018 the top three.
Toyota Innova maintained the best used price in 2019 at VND678-740 million ($29,220-31,890), followed by Chevrolet Spark and Ford Ranger.
Vietnam has been striving to develop its car industry for decades, but experts say the small market size has constrained local producers. The localization rate of passenger cars in Vietnam is at 7-10 percent, compared to 55-60 percent across ASEAN.
The country imported 133,696 vehicles in the first 11 months last year, up 95.6 percent year-on-year, mostly from Thailand and Indonesia, according to Vietnam Customs.
289,128 cars were sold throughout Vietnam in the same period, up 14 percent year-on-year, according to Vietnam Automobile Manufacturers Association (VAMA).