Choice of units - m vs ft / mi vs km

On some of the more recent watches Garmin give you the option of having different units for e.g. distance vs altitude (which is good).  However, I'm wondering if there's any way to do something similar with distance units - in particular, I prefer working in min/miles for pace when running, or mph when on the bike, but wouldn't mind (a) being able to auto-record the laps in km (or fractions of) or (b) having the turn-by-turn navigation use miles for longer distances (e.g. >0.5 miles) and metres (rather than feet) for shorter distances (e.g. <800m). Re. the auto lap, you can obviously set this to 0.1 increments but it would be useful if a couple of other fields were available (e.g. when working in miles a lap option at 0.621 mi would be useful - at the moment you can do 0.6 or 0.7...).

Suppose this isn't really a question - unless that question is, where can you ask Garmin for new features?