My wife understands her limits, which are pretty low on technical stuff. Her last car I gave her a shortlist of two, told her which I thought she'd prefer, and why. She tried them both and agreed.
Though she would still like a too-small-to-be-practical Cinquecento, and it must be coffee coloured...
Her skills are in other areas. She learned enough Japanese to be useful before we went on holiday there :)
Andy