I am a VP of Lending at a credit union that used to offer Payment Shaver loans. There is nothing fundamentally wrong with Payment Shavers. It is basically a lease look alike. They can provide you with lower payments than conventional financing. Only downside is you will ultimately pay more in interest over the life of the loan...particularly if you refinance the existing balance at the end of the payment shaver. With interest rates being at all time lows, I personally would take conventional financing and lock in the rates. Once the payment shaver balance comes due in 3-4 years and you refinance, you just don't know what interest rate you will receive--however, history tells us it will be considerably higher than it is now.
Good luck with the E and the financing. I sure love my Element!