When I saw this thread I rang the dealer and told him the part number and said "Put that thing in my car!".
The reason: if I"m driving along happy as Larry on a nice warm day heading into Victoria and I get into the alpine region, I'd like a little warning that my toes are going to fall off if I open the door. I'd also like some idea that it's so stinking hot outside that for everything's sake, I ought to be a little more conservative with the vehicle and not try to maintain speed up steep hills etc.
As for the wheels, I know the answer to that.
The Navara is sold to the Europeans and Brits with 17" alloy rims. Somewhere between the factory in Spain and the Australian dealers (might be the dealers themselves), the rims are changed for 16" but the speedo drive in the transmission is NOT changed.
As you guys probably all know (but I'll "say" it for those that don't), reducing the rim diameter will reduce the circumference of the tyre and therefore one revolution of the wheel travels less distance. The speedo, calibrated for the larger wheel, *thinks* you've gone further than you have, and faster than you are. Hence a speedo reading of 110 is actually about 98-99.
Hopefully I won't get a chance to test this: I told my dealer that I knew all this and wanted him to make sure that the speedo was accurate, because I want an accurate odometer. He acknowledged the practice and said he'd make sure the speedo was set correctly.
We'll see ... I should get to see the new car on Monday afternoon, although I won't be able to take it - it's a meet with the auto electrician, where I'll be asking for 6mm wire on my brakes & auxilliary power, and a pair of 30 amp thermal fuses protecting it all. Delivery should be later in the week.