Home Office and Vehicle expenses across multiple businesses?

I was wondering if anyone could provide some insight on how to distribute Home Office and auto expenses across multiple businesses. I have a web hosting business, three rental properties, and a regular full time job. In the past I deducted my vehicle expenses on the web hosting only, and deducted my home office expense under 1 of the rental properties in Turbo Tax.

Should I split the cost of the Home office expense across the three rental properties and the web hosting evenly or should I only take the deduction against one. For example: If the home office expenses were 4000.00

Rental property 1 - 1,000

rental property 2 - 1,000

rental property 3 - 1,000

web hosting biz - 1,000

Or should it be all under Webhosting = 4000.00

Also, for the vehicle if I used it for all business purposes, and no personal use should I take a % of the standard mileage for each business.

For example: SM = 4400

Rental property 1 - 1,100

rental property 2 - 1,100

rental property 3 - 1,100

web host - 1,100

Home Office and Vehicle expenses across multiple businesses?

Home office deduction would be apportioned among the business ventures based upon the amount of time spent on each one.

Vehicle expenses are easily attributed to exactly the appropriate business so are apportioned that way.

Note, all rental activities are reported on ONE Schedule E so you%26#039;d combine all of the expenses there.

Home Office and Vehicle expenses across multiple businesses?

web host 1000