Sorry I've been so long to respond but it's been busy around here and while I check in a lot of times with my iPhone, I'm nowhere near as patient as you are with trying to respond or post comments with it. I'm on my laptop this morning and thought I'd comment while I had the chance.
All three adventures you've posted lately starting with the trip with Bob and his wife, the get together with your brother and his wife and this latest one at the sports bars are the type of stories I love to read. I know what you said about it being feast or famine with your wife and your adventures but that's what makes it so hot. You never know from one moment to the next whether she will play or not and if she does, how far she will go. Those are the type stories that get me worked up like no other.
Not sure what kind of advice I can offer for exposing her while riding around other than wearing a long coat with little to nothing underneath but at the house is a different story. It's getting to be hot tub weather and that opens up lots and lots of opportunities of either naked games/dares or "getting caught" type scenarios. I'm sure you can come up with a fitting way to help her make good on her bet.
Looking forward to your next adventure!!