Hello and thank you for your question.
The 'how' aspect of your question is straight forward: simply title each vehicle under whatever business you want to be the legal owner of it. A business may buy the vehicle directly or the owner of a business may contribute the vehicle as a capital contribution.
The optimal strategy for tax purposes will vary depending on your use of the vehicle and related costs.
For either vehicle, you may want to use the standard mileage rate for tax purposes. This is the alternative to claiming the actual expenses associated with the vehicle: depreciation, gas, repairs, etc. Corporations and partnerships may not use the standard mileage rate method though, as this option is only available to individual taxpayers (either sole proprietors or employees using vehicles for work purposes). If you want to use the standard mileage rate method, which may very well be your best option especially with respect to the $5,000 vehicle because you won't have much to depreciate but may still put plenty of business miles on it, then you must retain title in your personal name and have the business reimburse you the standard mileage rate for business miles driven.
If you do not intend to use the standard mileage rate method, then you could put a vehicle in the name of your business and claim all the actual expenses for it. The business cannot deduct any of the vehicle expenses if it does not own the vehicle: it can only reimburse for mileage and deduct the reimbursement. The new car is a more likely candidate for deducting actual expenses because it may cost enough to the point where the actual deductions are more than that which could be deducted making mileage reimbursements.
Note that any personal use of a vehicle titled in the name of a business will result in income to the employee/owner, so be mindful of that fact too. If these vehicles are used 100% for business purposes it won't be an issue.
If a vehicle is owned by one of your businesses but (partially) used by the other one, you may also have some complications because the result is in effect shifting vehicle expenses from one business to another. If you plan to use a vehicle in more than one business, you may find it better to keep the vehicle in your personal name and take mileage reimbursements from whichever business you use the vehicle for.
I hope this is helpful.