Look at
Steelie mobile device mount , I use with iPhone with Co-Pilot on for navigation in 3.7 Roadster. Magnet very strong will hold an iPad.
I've seen the Steelie fitted to Adrian's car and it is very impressive.
However, I do note that in the small print, the makers will not accept liability for damage to, credit cards, computer hard-drives or. . . .
pacemakers! 
