Buckle crunch-car seat suggestions?

We recently bought a new car seat for our 10-month-old from Halfords online. Went to get it fitted and the assistant said because of our old car (1996 VW Polo) it would suffer from buckle crunch (where the car seat is pressed up against the buckle, which could come undone in an accident.)

His only suggestion was the very pricey MaxiCosi Tobi, which was like 170.00.  Don't get me wrong, I want my son to be safe, we just rarely drive and the car itself cost 250.00! I'm happy to pay around 100.00.  Does anyone have any suggestions for any other car seat that might work? Or had experience with this very problem and can suggestion a solution?

Thank you!

Places like Halfords and Mothercare will be able to tell you all models that will fit into your car. They have a computer that lists the majority of cars on the road and the best seats for them.
You can get a Maxi Cosi Tobi for £140 elsewhere from doing a quick search, so you may be able to find one a tad cheaper. Also, if you break down the cost over the years he will be able to use that seat (til he is 4), it works out to £35 a year. Not alot when you consider the safety and the importance of properly fitted carseat.