I've seen the Electristar fly, and when run with the recommended NiMH packs the plane seems to have plenty of power. Short run times are more of an issue, with 7 to 8 minute flights being typical of a pair of 3000mah NiMH packs. LiPo batteries would be an expensive but ideal upgrade to extend the flying time of the airplane significantly.
What would you recommend as an entry to RC aircraft, preferebly something RTF (or a kit that comes with everything) that isnt too big, is electric, and flys slowly.
Based on the original poster's description, however, I believe that the 63" wingspan of the Electristar might be larger than what he had in mind. Consider instead:
Hobbyzone Super Cub RTF
Parkzone Slo-V RTF
Both of these ready-to-fly electrics can be conveniently carried in a very small car and include everything you need to get them in the air. The Slo-V boasts an almost 4' wingspan, but flies so slowly and is so manuverable that it can be flown in a gymnasium if the weather doesn't permit outdoor flying.