Most appropriate time to go for baby 3 after Twins?

Hey everyone so I’m 20 years old and I’m a twin mum of 2 girls that are now 16 months old, we have a 5 seater sedan and I’m wondering how do people fit a third car seat inbetween twins??

I do not want to upgrade the car just now considering we recently bought it..

I want a 3rd child maybe in 2-3 years but even so how would that work with a 3rd car seat ? If anyone has ideas please show me how you master this skill

This is my car seat now which shows very little room in between and I don’t need to change the car seat as it fits my child until 7 years...

Pls post photos of your seats so I can get a better idea like how do you mums do it 😩