HOW TO CALCULATE PERCENTAGE OF VEHICLE EXPENSES TOWARDS RENTAL PROPERTY INCOME

I HAVE THREE RENTAL PROPERTIES - AND LAST YEAR I TRAVELED 300KMS IN TOTAL FOR ALL THREE FOR SHOWINGS. HOW DO I DISTRIBUTE COST WITH MY REGULAR ANNUAL TRAVEL OF 20,000 KMS. AND CAN I CLAIM SOME PORTION OF OIL CHANGE AND REPAIR AND MAITENCE OF THE VEHICLE AS WELL. I NEED HELP HOW TO CALCULATE THE PERCENTAGE FOR RENTAL PROPERTIES OF TOTAL EXPENSES.