Solar on the roof of the car is to Expensive and not practical. It is so much more cost effective to plug in, and you can find lots of places to do that.
If your commute is less than 40 miles each way, then just plug in at home, and install a 240v circuit for that.
If your commute is greater than 40 miles each way, then you can offer to pay for the electricity at work. If you get 4.0 miles/kwh, driving 40 miles uses 10kwh. At an electricity rate of $0.15 per kwh, the cost is only $1.50 each day. You can adjust this cost for the rates in your area. At work you can offer to work an extra 5 minutes each day to cover the cost of the electricity you use. Heck, you can even offer to work 10 extra minutes.
The cost of electricity is so cheap that it is not worth spending $5,000 to install an EVSE at work that will track and bill the cost of electricity. For Work Place charging a 120v circuit is all that you need. To re-charge 40 miles will only take a little over 5 hours at that rate.
Hope this helps.
2013 SL Metalic Slate
MFG 08/13 Dlv 09/06/13 @ 10 mi
12/27/13 LeafDD at 100% measured at noon (4,817 Miles):
259 gids, 96.93% SOC, 92.20 g%, 58.01 Ah, 19.7*c (67.4*f)
C 59.8475 V 395.5
# 77 100 mile club
# 10 200 km club