Tesla (TSLA) - Get Report unveiled updated versions of its Model S and Model X vehicles on Wednesday. Chief among them are stronger batteries that can propel the Model S from 0-60 miles an hour in 2.5 seconds. The only cars that accelerate at a faster pace include the LaFerrari and the Porsche 918 Spyder, which were only produced in small quantities and for a limited time. The Model X goes from zero to 60 miles an hour in 2.9 seconds. Tesla shares dipped slightly into negative territory on Wednesday. TheStreet's Scott Gamm reports from Wall Street.