It depends on the terms of your finance agreement. Many car finance firms have an insolvency clause in their contracts, but not all of them act on them as long as payments are kept up. Your creditors would also need to be satisfied that the car finance is reasonable before allowing the expense of the repayments.
My opinions are merely that .. opinions based on experience. Always seek professional advice.
IVA Completed 23rd July 2013 .... C.C. 10th January 2014 http://foggy.blogs.iva.co.uk
Have an anonymous call with them about their policy.
As Foggy says you have two hurdles to get over - firstly that creditors accept the expense as reasonable when looking at your disposable income to assess the level of any contributions you make and and then secondly whether the HP Company will allow you to keep it.