Tips:

1. Buy as low as you can and sell as high as you can (even if youre selling over market value just pay attention to the bar and keep it halfway into the green atleast

2. Customers can get annoying and constantly low ball you on your cars, stick to your guns and there will eventually be someone that will pay full asking price

3. Get employees as fast as you can and then you can start turning cars around much faster

4. Take advantage of the repair machine when you get it and constantly put things in and out of it to make sure you have the best parts and get the most money possible out of your sale. (wouldnt recommend buying non driveable cars until you get a mechanic, there is a search filter for conditon in the car ads for driveable and non driveable

5. Once you do have a body shop and mechanic person buy as many cars as you can and work them as much as you can to get the most value out of their daily salaries

6. This may be the most important one, take advantage of the odometer manipulator on every single car you put out for sale and lower the miles as much as you can without failing and it will pay off very well (Higher mileage vehicles are easier to take more miles off at a time, if its something under 20k miles i wouldnt go over taking off 100 miles at a time and just slowly fine tune it as far as you can into the red i like to get it around 90 percent)