At 500 miles on my car I decided to give it a whirl by accelerating speedily and hitting 5k rpm. I shifted into first and gunned it and when I shifted into second at 5000 RPM there was a noticable thud sound. I am pretty new to manual transmissions in general and my shifting might not be the greatest, but I remeber some one mentioning that when they're motor mount went out that they heard a thud when they shifted. I was wondering if this 'thud' was piss poor driving on my part or if it is anything I should be concerned about. This was the first time I have heard the thud. :?