I assume you are referring to an 850 model wagon. Awesome car :thumbsup:
The only advice I have for that car has to do with the knob adjusters on some (all?) of the Evenflo convertibles. They are difficult to install RF outboard in the 850 & S70 sedans because the rear seats are contoured, and the wheel well is in the way of the adjuster knobs. if that is the type of carseat you have, and want to install outboard, I would try it in the wagon to see how it works for you.
Otherwise I love, love, love that car!!! I have a 98 S70 (same car, accesorized slightly differently) with almost 150k miles & its great.