I rent cars several times a year from several different companies (whatever is the cheapest) and I never experience upsells, let alone "high pressure timeshare

I rent cars several times a year from several different companies (whatever is the cheapest) and I never experience upsells, let alone "high pressure timeshare tactics." Are you speaking from experience, or just assuming this is how car rental agencies operate? Edit: they do ask about pre-buying gas and additional insurance, but a simple "no thanks" ends that part of the transaction immediately. Are those the upsells you are referring to?