Some of that doesn't scale rapidly. If they need to buy a thousand car washes nationwide, an owner in Omaha is not going to sell at a discount just because they already own 10 car washes in Los Angeles. Similarly with pricing for gas/electricity.

Their economies of scale are akin to those of Avis or Enterprise Rent-a-Car, and those companies are not valued at high multiples, due to high upfront capital requirements, insurance burden, fast depreciation, low barrier to entry, etc.

Current multiples for Uber are there precisely because of the lack of all liabilities associated with car ownership and maintenance.