The stunning teen - who prefers to be called Liza - is pictured wearing white sunglasses and showing off her long legs on the bonnet of the white Bentley Continental GT V8.
The luxury car is worth about 10 million RUB (£830,000) but experts say the price in Singapore could be much higher due to high taxes on registering the vehicle.
The couple's controversial romance allegedly started more than three years ago after Miss Adamenko left her Siberian hometown of Kansk in central Russia's Krasnoyarsk Krai region.
Russian publication Prospekt Mira reported the pair had started dating when Miss Adamenko was 14.
The age of sexual consent in Russia, as well as in Singapore where the couple live, is 16 years.
But the fact that their relationship was potentially unlawful and could have ended in jail for Mr Romanov did not keep them apart.
In July this year they married at the Chateau Saint Jeannet, a famous castle and upmarket wedding venue, near the beautiful village of Vence on the French Riviera.
Pictures on social media show the young model who has posed for Vanity Fair, showing off the car, as well as with her husband at glamorous locations around the world.