I am a sole proprietor and I notice that I can enter my vehicle expense in two places, one under my business expenses and the other under rental profile. Which one?

If you used the vehicle for both purposes (and qualify to claim it as rental expense - not all rental owners qualify), you can enter the vehicle in both sections and take deductions for each assuming you kept a log for both ventures as well as the total km driven overall in the year.

Here's a link for more information on eligibility for claiming vehicle expenses as a rental owner: https://www.canada.ca/en/revenue-agency/services/tax/businesses/topics/rental-income/completing-form...