No hay nada imposible hombre.
Si que se puede montar, simplemente es algo diferente al tempomat electronico, mira:
https://www.google.es/search?source=hp&ei=397DWvu2CNHWsAHuwpmQDQ&q=montar+tempomat+en+a6+sin+acelerador+electronico&oq=montar+tempomat+en+a6+sin+acelerador+electronico&gs_l=psy-ab.3..33i21k1j33i160k1.1406.15514.0.15644.60.39.2.2.2.0.482.4810.0j4j7j4j2.17.0....0...1c.1.64.psy-ab..39.17.3368...0j0i131k1j0i22i30k1j33i22i29i30k1.0.RVMbBbs_dRE
https://www.google.es/search?ei=8N7DWtieD4b9UJinl5gE&q=montar+tempomat+en+a6+con+acelerador+por+cable&oq=montar+tempomat+en+a6+con+acelerador+por+cable&gs_l=psy-ab.3..33i160k1l2.27164.33472.0.33570.50.22.0.0.0.0.404.3520.2-5j5j1.11.0....0...1c.1.64.psy-ab..41.7.2270...33i21k1j0i22i30k1.0.iY7nMjzTtBk
Suerte, ya nos contaras.