For 2020, Toyota is giving the Prius Prime an extremely modest update, highlighted by the addition of a fifth seat – the previous version only had belts for four occupants. Toyota also switched up the naming architecture of the trim levels to better align with the branding of other cars such as the Corolla and Camry. The mild changes are reflected by slight increases in starting prices.The Prius Prime's main draw, its 54 mpg combined fuel numbers and 25 miles or estimated electric range, remain exactly the same for the 2020 model year, but Toyota made slight alterations to update the model. Most notably, the rear seat has been changed from a two-seat configuration to accommodate a third middle seat. The old model features an arm rest and cup holders between two seats.Toyota also upgraded the Prime's tech. For 2020, it comes standard with Apple CarPlay compatibility, Amazon Alexa capabilities, and two extra USB ports for the rear seats. Small nips and tucks include a new sun visor extender, black interior accents that replace white accents, and relocated seat heater buttons.As part of an overall brand alignment, Toyota ditched the 2019 Prime's Plus, Premium, and Advanced trim naming strategy. They will now be called LE, XLE, and Limited, and each gets a slight price bump. Before destination, the LE will cost $250 more than the Plus, the XLE will cost $450 more than the Premium, and the Limited will cost $150 more than the Advanced.From a sales stand-point, the Prius nameplate has been suffering in 2019. Per Toyota's April 2019 report , it has sold 16,857 Prius models, down 43.2 percent from the previous year's sales of 29,655. Toyota does not break down specific sales of the differing Prius models, so it's unknown what part the Prius Prime played in this. There could be several reasons that contributed to the downturn: Gas prices have been low, new electric vehicles have been introduced and are becoming more common, and Toyota introduced the much more normal-looking Corolla hybrid . Maybe this more family-friendly package will help attract new buyers.The 2020 Toyota Prius Prime will be available this summer.