i'm here too 
wiggly baby on my lap so can't say much right now!
Because you know that he can hold it, this is what I do, I take his nappy off where I would usually change him and then carry him to the sink naked, he's never wee'd on the way to the sink, then he can do his business and then carry him back and wipe and put a fresh nappy on or keep nappy free, I usually keep nappy free for a while after a wee because you know he's just done his wee so he's not likely to do another 
We used the sink for maybe a week or two before starting to use the potty, but that was mostly because he was only 6 weeks when we started and I didn't feel too confident using it, but advice readyORnot gave me was to not make it about going for a wee, but to make it a bit more playful using toys, that helped us, so we would just sit on the potty a few times just to get him used to sitting on it, then he loved it really quickly and it's much easier than going all the way to the sink 
) cued him and he did a lovely wee in the car, nappy back on, back into his seat and we were on our way and he fell asleep once he got that out Such a proud mummy moment 
Sounds like you are already off to a great start
Oh I also have that book, I loved it, very helpful, that reminds me, I only read the first bit as decided i'd take one step at a time, but I guess I should delve further now that we're army crawling
I just want to share a good day we had yesterday, we went to do the food shopping, we went for a wee on the toilet before we left the house, then after we finished the shopping, I loaded it into the car and decided I needed the toilet so we went in and first I tried Loki, he did a big wee (although he had a wet nappy, not sure when he did that wee!), then we went to pick DH up from work and took him to the chiropractor so waited in the car for 15 mins playing and then having a feed, then half way home he needed another wee, so I pulled over got out our portable potty (which is just a small dogs water bowl
comes with the territory i'm afraid, and not the end of the world, I think I change more than he does anyway, he's always sick on me rather than himself Also I use re-usable wipes with water, so if I think he's doing a poo I have a cloth ready to wipe straight away, or once when he did a poo in the sink, I just filled up the sink with some water and gave him a mini bath to wash it off, he quite liked that I've got 30 nappies and I wash every other day, some days he can be in the same nappy for almost the whole day though 
any suggestions?
We sometimes go through more nappies than if we didn't EC because if I think he needs a wee I check, and even if it's a little damp, I won't put it back on, he may have only had it on 5 minutes, but it's a wasted nappy, although we use cloth so not a "wasted" nappy
I think it just reminds him that i'm trying to help him as I can acknowledge every single wee, even ones on the floor, rather than only noticing the ones we catch on the potty 
