The most important thing IMO is what is his motive? If he's doing it up for himself there's some merit as tastes are personal. If he's doing it up to get positive attention from other enthusiasts (and I reckon he probably is if you're posting here for him asking what people's reactions would be) then he may as well give up now.
There's certain cars that no matter what you do to them just don't cut it. I had a Daihatsu Charade GTti, which is a 3 cyl, twin cam, turbo, intercooled, injected etc etc little rocket which I modified and tuned till it would hammer all my mates in their Commodores, pulled 200 km/h (which in a Charade is seriously scary) and sounded sweet as. But at the end of the day, it's still a Charade/shopping trolley/chicks car and those were the sort of comments I got. For me, that was fine, it was a cheap, fun daily that didn't cost the earth to run/modify. But if your mate wants positive attention from other people, he won't get it in a riced up Lancer.