I've been known to offer unsolicited advice a time or two myself....
I usually find people either looking really confused, arguing, or picking up a 3-in-1. Usually if it's one of the first two scenarios I just try to make eye contact and say something like "Its a tough decision hey? Who are you shopping for?" And then go from there. I try and get age, height, weight and budget before making any kind of recommendation. I have found almost everyone very receptive. Especially if I say something like "You know, considering the information you've just told me, I think the TF, EFTA, etc. (whatever the case might be), would be a great option for you, and here's why...."
If I see someone picking up an AOE or the like, I usually start with something like "Oh I had that seat and I hated it (lie, lol). My ds grew out of it before he was 2.5 and I ended up sepnding twice as much in the end because I had to get another harnessed seat." People tend to think with that approach that I'm just trying to save them money, which seems to be a pretty good motivator. They usually ask "Oh, so what seat is better?" And then I point them to the EFTA or tell them about the TF. (Because its usually at Walmart that this happens.)
Every time except one I have managed to "convince" them to get a decent seat for what their needs were. The one time it didn't go so well was when I talked to them at TRU and pointed them to the TF at Zellers on sale, and then I ended up having to go to Zellers for something and I saw them again there and I think they thought I was some sort of whacko, lol. Oops.
And I'm pretty sure TJ's hates me because I haven't bought a seat from there since last year and I'm always hanging out in their car seat aisle. Plus I'm always asking about whether they're getting the Monterey, GN, Frontier, etc., or telling them about the Frontier harness issues, etc., and I think I make them feel a little bit out of the loop. Most of them are okay, but there's this one manager that I know doesn't think highly of me. Then again, maybe its my kids. She seems to not like it when I bring them all in at once.:shrug-shoulders: I kinda thought with a name like "TJ's the Kiddies Store" they wouldn't mind if you brought kids in.