Here's how the scam works... They show good rates so you rent from them. You have to pay at the rental desk. Then you return home from holiday and discover you've been billed twice - once by Enterprise and once by Carflexi. You complain and they tell you that one of the bills was for what they call Premium Excess Protection. They said you would get this at the booking stage but at no point did they say you would pay extra for it - Eur 126 in my case. I can't easily pursue them as they are a Swiss company but if I could establish that the Eur126 that Enterprise collected from me was for the insurance then I would take them to the UK Small Claims Court in a heartbeat.
Shame on you Enterprise for climbing into bed with these crooks. Even as a loyal customer I will never use you again.