Maybe you need to sit down with the car and assess the project from where it is now and where you would like it to be in say 3 months.
Make a plan, not a deadline, but a plan so you don't get discouraged if you don't meet a deadline.
What small things are there that you could do to it in a spare hour or two here and there (Like cleaning)?
Knock those small tasks off your list and you will get motivated to do more.
I find that the hard part is getting going, and after that i get right into it.
Consider it a series of small projects, not one big one!
Beer and music does help too...............