Nope. Not that I know of anyway (and if there are any, it's better that I don't know).
How'd you manage with the youngin' and the Ducati though - that's my point. If you made it work with the bike, I imagine the TT would be a step up. I was in a similar boat going from commuting on my Katana about 75 miles a day at my old job to the car. Fortunately I didn't have my decision forced for me by an errant coyote or anything, but I got sick of being dependent on 20-year-old 944s with questionable reliability and that I constantly had to wrench on to keep running well and a motorcycle that (although I loved) was eventually going to end me up injured if I continued to use it every day.
Still riding regularly, but more for fun and more local. But mostly driving now. A child seat should fit okay in a TT. . .
The A3 is a great car - my friend's wife bought one about a year ago (and they have two hellspawn). Works great, she raves about what a great car it is and it seems nice.