American cars have the steering wheel on the left side.
Literal
American cars' steering-wheel [topic-は] left-side [at-に] exists.
ハンドル is the Japanese loanword for 'steering wheel' (from English 'handle'). 左側にある places it on the left using 側 (side) + にある. A cultural comparison point for Japanese learners, since Japanese cars have right-hand drive.