It's all in the hips

My version:

(While gently moving Taylor's legs to and fro.)

Motor boat, motor boat, go so slooooow.

Motor, boat, motor boat, go so FAST!

Motorboatmotorboat step on the GAS!

B's version:

(while not so gently manipulating her brother's lower half back and forth):

Motor bo, motor bo, slow

Motor bo, motor, fast

motor bo CRACK!

(On cue with "CRACK", initiates extreme middle split position.)

Good things babies are so flexible!