Mischa Barton blonde beautiful convertible blue gas

After a hearty meal yesterday at a West Hollywood restaurant, Mischa Barton got gas -- at the service station, y'all, for her car!

The quirky actress filled up her classic convertible and we can only imagine this thing must be quite a gas guzzler! This boat's no Prius, people, but it is cute!

But Barton better watch out for more than gas prices, she's chatting on her cell while pumping which is a big no-no! Check yourself before you combust yourself, Misch!