The road is known locally as the ‘ski slope road.’
A blue Ford Kuga car was set on fire about 12.05am.
Scottish Fire and Rescue Service put the fire out but the car was badly damaged.
Constable Hannaford-Bennett at Cumnock Police said: “Enquiries are underway into this deliberate act and I am appealing for anyone who may have been on the ‘ski slope road’ late on Sunday night or early on Monday morning to call police if they saw anything suspicious.
“If anyone was along this road and had a dash cam fitted we would also like to hear from them.”
Callers can contact police on the 101 number and should quote the incident reference 0179 30/9.
