I am a tradie and want to purchase a new work car. The vehicle I am looking at is brand new and fits in with my work requirements, so it will be 100% for business. The retail cost is $35K, but I am trading in my old vehicle and getting a good deal so the price will come down to $22,000. But I only want to purchase a car if I can write-off the whole amount. Any advise on this would be great.