Erf group 1 car seat to fit in a Suzuki Wagon R?

[TeaRex]

Does such a thing exist or an I kidding myself? My dd's just turned 1 so I'm thinking about the next step though she's got another month or two in her maxi cosi.
No isofix in my car so I'd need it to be fitted with a seatbelt though my husband had isofix in his golf so one we could switch between cars with relative ease would be great but if not it's more important to fit my car. Any ideas and if not any recommendations for ff?
Thank you for your help, I feel like my heads going to explode with the choices :)

Hi Tea,

Not much help from my side. I've bought 3 different models already and none of them seem to fit our Wagon R (2 rear seats), basically, the child car seat is really loose after tighten the seatbelt to its maximum :(

Did you manage to find a specific model that fit the car? or how did you do?

Many thanks!