Dealer priced a 2004 E55 AMG with 45,000 miles for 43K

Comes with:

Pano roof, solar panels, auto trunk close, bi xenos (lighting package) and has CPO 12 months or 100K

Downside.... No navi...

Questions:

Dealer states that they traded it in for 41k and 43 for the warenty... Good price? Others from indy dealers in the area start at 39K

How effective are the solar panels?

Thanks!