Why would any dealership settle for multiple websites to support their multiple locations? This isn't a good choice and here's why...
Most importantly, WHY would any multi location dealership inhibit website visitors to view ALL their inventory together and force them to visit additional pages to view each locations inventory? When a visitor is on your lot, would you prevent them from learning about inventory at another location? Your website is a billboard of EVERYTHING you represent.
Too many domains will confuse the engines. All your inventory needs to live within your primary domain and the engines will certainly fall in love with you.
Your inventory should be specific to your location. It's important that your inventory URL's are relevant to each location which should include the city and state. Google loves that!
Your website should give your visitors multiple opportunities to search inventory all together or by location. Remember your website visitor may be hundreds of miles away and multiple locations may not matter to them. They want to see it all, so give it to them in one click.
Your details pages should be location relevant too. Include Google maps and directions. Perhaps graphics with hot deals for that one location.
All forms on your website should get delivered by location to the correct team member. These are all the important steps that we take to insure that our multiple location dealers are getting the finest exposure and ranking they possibly could.
If any provider tells you different, it's because they probably don't know how. Challenge them and demand your site is combined into one.