I received the PadHoldr yesterday and installed it in my '06 Toyota Sienna. Some observations:
1) The PadHoldr itself is well made and good looking. I think it needs a few minor refinements; I sent an email to Jim with my comments.
2) The car mount bracket is from PanaVise. It was originally designed to hold phones and such, and is simply not up to the task of supporting the much heavier iPad and PadHoldr. The bracket for the Sienna attaches to a single 10 mm bolt which screws into a plastic socket in the dash - not what I want my $800 iPad hanging from! The bracket itself is thin of necessity to fit between the panels in the dash, but as such it is not stiff enough. The iPad wiggles from side to side constantly when the car is in motion.
The Sienna has a flip up center tray with cup holders attached to the driver's seat. I drilled 4 holes in the front right cup holder and bolted the PadHoldr base to this. This is an excellent solution! It puts the iPad in a very good location, easily reached and viewable. I didn't think I'd like it this low but after driving around for a day running GPS Drive HD and listening to a book from Audible, I think it's just fine. It doesn't block any controls or the air vents. It also keeps the iPad a bit more out of sight than if it were higher up.
I took a quick picture with my phone:
http://lunatech.smugmug.com/Other/OddsEnds/IMG0362r/961752017_kGcWe-M.jpg
Another option might be to use a longer extension arm from PanaVise and a bracket of some sort to bolt it the passenger seat track. I've seen a solution similar to this on eBay (but it had a laptop tray on the top).
I keep my iPad in an Apple case; the PadHoldr comes with a different set of spacers intended to allow inserting an iPad which is in a case. I found that I needed to add some washers to make a little more room.
The iPad works best if you insert it "upside down". Otherwise it's pretty difficult to reach the volume control or power switch. I suggest turning it around and setting the rotate switch to lock the postition before you insert it in the PadHoldr. A couple of times driving when I hit a bump the screen rotated and then came back.
William