Unfortunately, if your employer uses a "scheme" then the middleman creams off the 15% that the employer would save, then jacks up prices well beyond the market because they have a captive audience.
If the employer leases the car themselves and provides it to you as a benefit, it can be good value -- but then someone has to own the risk of you changing jobs.
If the employer leases the car themselves and provides it to you as a benefit, it can be good value -- but then someone has to own the risk of you changing jobs.