Apex domains cannot have CNAME records.
Question and response
Question
dig internetcarhire.com. NS
Answer
internetcarhire.com. 1 NS ns-1643.awsdns-13.co.uk.
internetcarhire.com. 1 NS ns-1668.awsdns-16.co.uk.
internetcarhire.com. 1 NS ns-67.awsdns-08.com.
internetcarhire.com. 1 NS ns-343.awsdns-42.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0