did your tax guy explain to you that the rental of the truck would be a trade or business of equipment rental. you would report the the rent on schedule C since it's personal property rental. expenses including depreciation and interest paid on the truck loan are deductible to the same extent business mileage is to total mileage. business mileage does not include commuting or other personal mileage. the loan principal payments are not deductible. the rent has to be fair value if not the IRS could really have a field day if your audited.
another way to handle the truck operating expenses is to have the S-Corp pay them - but that would mean less in rental income
do you actually have a lease between you and the S-Corp. If audited the IRS probably would ask to see it
also the S-corp would have to issue you a 1099 for the rent it pays you.
also you should talk to your insurance agent about coverages on the vehicle to make sure both you and the S-Corp are protected. Another thing to talk to agent about is workman's comp insurance. state laws differ, but in my state even a one man S-Corp is required to have it.
my feeling is that your setup has unneeded complexity..
