If Disney Princesses don't want to make you gouge your own eyes out, this Group 2 - 3 High Back Booster Seat is available from Argos, reduced to £24.99 from £49.99.
While Argos doesn't provide safety testing information on this seat, they do tell you that it has been 'styled to provide not only safety but a fun place for your child to sit all the way from 4 to 12 years old'.
It's a Group 2-3 seat, so suitable for children from 15kg to 36kg, and it fits both the front and back seats of your car, although it is recommended for rear seat usage.
It requires a regular 3 point seatbelt to fasten into the car and can be used forward facing only. Despite it's name, it does NOT convert to a booster seat later on (the bottom bit only).
The Princess car seat provides side impact protection, a seat belt guide in the headrest and adjustable head support, along with armrests and a padded seat with a hand washable removable cover.
Thanks to dizzydee2009 at HUKD