We tested the seat out in our car before purchase but we made an unfortunate mistake. We fitted it in the car without the headrests on and then found out after purchase that this model is supposed to only be used with the headrests. The reason the headrests were off was because the previous brand of booster seat that we were using did not require the head rest to be on if it prevented the booster seat from sitting flat against the back of the seat. Although, the staff we dealt with were great - very friendly, helpful and accommodating - I wish they were trained to be more knowledgeable in car seat fitting. We missed a crucial piece of information and could have easily purchased a different model had we realized (we bought our previous ones from Snuggle Bugz). Ideally there would be a quick reference guide that the staff could refer to that details the fitting requirements of the brands they carry, and they would go over this with the customer at the time of purchase or testing. I can only blame ourselves for this mistake but I do wish the staff were more proactively trained to catch these types of issues, as car seats can't be returned and there are safety issues involved. It's not like it's a toy or an article of clothing.
The car seat itself is lovely, nice material, fairly slim, and easy to adjust. As long as your headrests don't protrude forward, as many of the new models do, I would recommend it. Just make sure to check the fit better than us!

Second time buying this car seat and we love it!