YOU SAID:
My car is very speedy!
INTO JAPANESE
私の車は非常に高速です!
BACK INTO ENGLISH
My car is very fast!
INTO JAPANESE
私の車はとても速いです!
BACK INTO ENGLISH
My car is so fast!
INTO JAPANESE
私の車はとても速いです!
BACK INTO ENGLISH
My car is so fast!
That didn't even make that much sense in English.