Spain/Portugal/Gibraltar - Arguscarrentals.ca - to book or not to book a car in Madrid

Has anyone had any experience renting cars at the Madrid airport pre-booked through arguscarrentals.ca. I found them through an ad they had on kayak.com

The inclusive rate quoted was really great, but the reviews I found on google for argus in general were really bad. This is either their competition dissing them, or they really do suck.

Any assistance that anyone can provide is welcome. I don't want to make a bad decision.

Welcome to FT!
Are you asking whether or not you should book a car in Madrid, or whether or not you should book a car in Madrid through argus?

In the former case, if you're staying only in Madrid, the answer is: no, don't book.
In the latter case, it seems they are a consolidator, dealing with multiple partners, so the service quality really depends on who you get in the end.