I presume I can claim back the VAT and offset the cost of the vehicle against my quarterly tax return?
Yes, you can. However, there are quite complicated calculations involved, meaning you'd be wise to use an accountant to ensure that you do it properly.
Generally speaking, a much easier option is to buy a car personally, then just claim so-called "kilometrówki" based on the kilometres driven for business use.
You can't claim VAT back with this, but 0.84zł per km driven for business purposes isn't bad.