Changing careers whilst eventually studying to change careers again?

I currently work in IT technical support and have progressed from 1st to 2nd line technical support over 2.5 years (currently 22 years old with no degree), i'm really uninterested in the industry and my job and am keen to go back to university part time while working to study for an environmental science degree to eventually go into that industry.

The catch is i cannot stand waiting another 6 years working in IT, the jobs pay poorly in the UK and the work i find is monotonous and uninteresting or way above my skill level with employers not willing to offer training and no motivation to train to reach those levels.

I have a very keen interest in the automotive industry (basically i'm a car nut) and there seems to be a glut of service advisor jobs earning about £30k-£35k with minimal entry requirments, is it a bad idea to try and apply for one of these jobs, work in the industry for the next 6 years and then apply for a graduate scheme within government to enter into environmental science.

Is this a dumb idea, if so what would be more sensible.