Both sentences are in future tense, however the first gives the person you are speaking to the impression of showing the special car in the far future. The second implies you will be doing it sooner. Adding or omitting the 'be' from sentences makes the difference.
For example: if a teacher tells you "I WILL BE teaching you derivatives in this class" implies he will not teach it that day.
But, if the teacher says "I WILL BE teaching you derivatives TODAY" it obviously means he will do that immediately.
I hope this helps :)