Be honest. They have the right to come in and inspect your records at any time.
You will pay NO taxes when buying goods. Once you sign with them you get an exemption number that you can give to suppliers that allows you to buy without paying sales tax.
You must COLLECT sales tax on any sales in Michigan - unless whoever you sell to provides YOU with THEIR exemption number. You must have a copy of their exemption or file, or collect the tax. This costs you nothing, you simply pass on what you collect, keeping a tiny amount for your trouble.
BUT, if you do not collect when you should have, then YOU will owe anyhow. If you make a sale in MI and do not collect the tax and do not have an exemption - you are liable for the tax.
Sales outside MI are not taxable. You can sell anywhere else in the world and you are OK. Just sales within MI.
Of course, if you make any profits, they are taxable as income, just like your earnings from Ford. Whole different deal. You would own income tax no matter how you get that.
In my area Ford just closed down a whole plant. Been making pickups for years, just shut her down. Years ago I used to sell truck parts to NuCar Carriers who were hauling the stuff out for them at the time. Of course, the car haulers are gone too, as well as a lot of warehouse and parts hauling operations. A real shame.
.