Hi Yokev: Thanks for your response. Before I posted, I scanned the whole site for alternative spare mount ideas and there are some posts but I could only find one other query about the Wilco option and this was the only reference to a rear mounted spare I could find. I posted my query in two subforums because, like me, I'm sure most of the group do not scan all the subgroups or all new posts and I wanted to ensure that this query was most likely to be responded to.
The only carrier I've seen relating to the ZR2 is a bed-mounted one; I'm not interested in this option; I'm inquiring about rear Hitchgate styles. I have not been able to find an aftermarket Colorado bumper with a swing out carrier option.
If you'd read my posts you would note that one of my concerns is that my underhung spare is too small (33" vs 35") and has a different offset from my bigger, aftermarket rims. This makes me very wary using it as a spare as running a mismatched wheel for any length of time would stress the drivetrain.
Also I bought my truck as an expo/camper base so using-up valuable bed or roof space for the spare is not an option. You are quite correct that most people would leave the spare underneath but I plan to buy a 5th oversize rim/tire and even if it did fit under (don't think there's room), I would not choose to do this. Dropping an underhung wheel on pavement is easy but based on personal experience, this is rarely the case offroad and it's more likely that I would suffer a tire failure offroad than on.
As a bonus, the empty spare tire spot leaves loads of room for an ARB on board air compressor, air tank and house battery.
Rick 2016 Colorado Z71 Crew Cab, long bed
BDS 5.5" lift, Fuel Vector 20x9 rims, Toyo Open Country AT II Extreme 305/55R20 tires
Bushwacker pocket fender flares