We have 3
carseats! One console lookout which Rowdy loves - but now that we have Rexy too - we have another that hooks onto the passenger seat - but..... after reading livingdustmops post a few weeks ago, we got a buddy lookout so the both of them could ride in the backseat. Now, we only tried it out day before yesterday and I was surprised that Rowdy tolerated it as well as he did - he's used to being on the console so that he can lay his head on my shoulder.
Anyway, he did OK and so did Rex. The only problem is that their straps got crossed when they switched sides. We have a looong car trip coming up in June - about 15 hours over 3-4 days, so they will get plenty of riding practice.
Note: the buddy lookout is waaaay bigger than I thought it was - so if you get it, be prepared. I do think it is the way to go for us because Rex is only 3 months old and he wants to be with Rowdy. Rowdy, on the other hand, kinda wants to be wtih him and kinda not - so we'll see how it goes.