Ok squid made a few ajustments for you.
Ok firstly you were on the right lines with the offset sprite but rather than:
offset sprite 2,sprite width(2) / 1,sprite height(2) / 1
you want
offset sprite 2,sprite width(2) / 2,sprite height(2) / 2
as this means your car will turn at the centre of the sprite looking much nicer.
also
`SET PLAYER MOVEMENT
If rightkey()=1 then angle# = angle# + 4.5
If leftkey()=1 then angle# = angle# - 4.5
If upKey()=1 Then Move Sprite 2,8.2
If downKey()=1 Then Move Sprite 2,-8.2
i have no idea how you normaly play games but for most of us this is easiest !
Also i have rotated the car sprite left so it drives forewards rather than sideways !
Hope that helps, good luck
<EDIT>
Also youll want to resize your main menu to 640x480 so it fits.