Replace rear seat belt buckles

[cythraul]

Hi,

My two oldest daughters (5 & 7) are using boosters while my youngest is still in a regular car seat (Radian.)

Unfortunately, the seat belt buckles are nearly unreachable. I was hoping to use seat belt extenders but apparently they are not approved by car seat and booster manufacturers.

So I'm looking at replacing the actual belt buckle by a longer version. Did anyone attempted this?

Thanks!