On reading what I assume is an extract from Shiply's website, the reference to the relatively short lifespan of the Covid19 virus on soft surfaces doesn't actually apply to cars (or indeed car parts). My understanding is that the virus can survive for up to five days on metal and other hard surfaces, in which case, unless any car related purchase was to be quarantined for five days on arrival at the buyer's address, there is a risk that any virus from the seller's location would be passed on to the buyer and his/her household, even if only a car part was bought.
The risk brought about by the length of the journey would be the potential for any virus attached to the collection driver, including any picked up from the seller, along with any from subsequent drivers and warehouse staff in the case of many courier services, to be passed to anyone encountered en route, or anyone coming into contact with any surface touched by the driver(s) during stops.
I suppose the decision whether to continue buying and selling (and of commercial enterprises to facilitate such activities) during these deadly days depends on the consciences and social responsibility of those involved.