Taxi's overseas without a car seat - advice please!

[MummyLostInParenthood]

Hi all! I am travelling with my 6 month dd next month. We're flying to Zurich and staying a few days for a friends wedding. Then flying to Sofia in Bulgaria and staying overnight before taking another flight to the Bulgarian coast.

We will be staying with family in Bulgaria, and therefore don't need to take a carseat, as my parents have bought one for their car for her.

My concern is that we'll need to take some taxis during our stopovers in Zurich and Sofia. I'm hoping we might be able to find a taxi firm that has car seats available in Zurich, but my parents have said it's unlikely we will find one in Bulgaria. It's not law that children need to travel in car seats the way it is here.

Does anyone have any advice? What is the safest way to travel in a car without a carseat? Is there any other solution? Is it possible to buy seatbelt attachments for your lap like in airplanes..?

Any suggestions will be gratefully received!

I would have thought that your journey would be much easier if you bring your car seat with you - will that not be easier for you on the plane anyway if your baby wants to sleep?
I had a travel system when my DD was that age so we took the car seat and wheels to use as a push chair, but if you have a separate buggy then I guess you will be taking a lot with you. However at that age I think it's really important that they're in a car seat and the only way for you to ensure that you have one for each journey is to bring it with you.
How would you be travelling to the airport in this country, would you not need the car seat then too?