That is b/c the SHO is in high demand compared to those other cars so the lease rates are not as attractive. Also the SHO is the high end model with a base MSRP of 37k and hits 45k loaded.
The lease rates on the G37, IS 250, A4 are for base models with no NAV....
The new Taurus SHO is badass and BETTER than the other cars listed there.