Lexus is taking a close look at even more efficient versions of its new CT200h premium compact hybrid, while hinting that a high-performance version of the car is in the works.

During a product presentation of the CT200h at the car’s global launch just outside Paris, France, Lexus College manager Paul Williamsen went out of his way to point out that the current battery pack located in the rear of the CT doesn’t take up all of the space. The larger area, “could ‘theoretically’ be used to put a larger battery pack with increased capacity,” he said.

This news coincides with previous reports that Lexus has also filed for patents on the CT300h and CT400h names.

Currently the CT uses a hybrid powertrain similar to that found in the Prius, making 134-hp and delivering a 0-60 mph time of 9.8 seconds.

In addition, Osamu Sadakata, Chief engineer for Lexus hybrid vehicles told media present that both a plug-in hybrid version of the CT200h as well as a version using a more efficient and compact lithium-ion battery pack are possible. Sadakata said the shift to lithium-ion battery technology is, “the way of the future” and that a Li-On CT is “technically possible,” but stopped short of confirming a CT using the more advanced technology.

As for a plug-in CT, following after the plug-in Prius, Sadakata said that it would depend on market demand, both for the system and for the CT in general. “If we have the demand, as Chief engineer, I could like to bring it to market as soon as possible.”