Here is a low cost, $975 US plus shipping, option that would attach to an existing tad pole trike. This kit is a fabric covering that connects to your recumbent trike that could help overcome mild weather. The website states that it is not intended as an aerodynamic advantage and should not be used above 25 mph. It could however be used to keep you out of the rain without adding the cost of a full velomobile. It also collapses down to a very manageable storage size. This could be the ticket for those of you looking for an affordable covering for part time use.