All,
I had been looking for a while for a car seat for my 2003 SC430 and even spoke to my Lexus dealer (who claimed to look high and low for a car seat) as well as a few on-line car seat providers that also could not find a car seat for the car.
I eventually also came across the Combi Coccorro which I thought I'd take a chance with. Other people with small cars claimed that it was a life saver, so I bought it.
Item At Amazon
Well, I'm thrilled to say that it seems to work perfectly! Interestingly, I knew the car had LATCH in the back seat because I had put a base in the car when the baby was smaller. But I couldn't find the "upper LATCH" until I brought it to a place to help me install it. Turns out that there IS a LATCH connector on the back side of the headrest which allows for a very good fit.
Here's a picture of my happy son riding in "Daddy's Car"...
Happy Boy In Car Seat
Only downside is that the seat only supports children up to 40 pounds, so I may only get 6-9 months out of this (he's a big boy), but the idea was to help my wife so she wouldn't have to take him all the time to day care.
Good luck all.
Thanks,
Eric