This may be useful if you want to compare the results from similar searches or if you don't want to open too many tabs and clutter your browser.
You can also add an initial part that repeats for each search, like rent// bmw ++ citroen ++ chevrolet. This will open three tabs that search for: rent bmw, rent citroen, rent chevrolet. There's also a repeating end for your query: rent// bmw ++ citroen ++ chevrolet \\in ny
While not cutting-edge, the site has a set of interesting options like: searching feeds and previewing them, saving group of tabs and searches.