The way I do it is when you enter that room, if the first Thwomp is moving to the left or right, pass it and start a wheelie and you'll get past the second one. If the first one is coming back after hitting the wall, the second one will block the passageway so I would start to drift to get past it.
Kimi wa ne tashika ni ano toki watashi no soba ni ita
Itsudatte itsudatte itsudatte
Sugu yoko de waratteita
Nakushitemo torimodosu kimi wo
I will never leave you