i had an inline 4, rear wheel drive liftback before. installing an auxiliary fan in front of the radiator did wonders to my aircon woes, traffic and highway.
today, all front wheel drives have aux fans in front of the radiator or aircon heat exchanger.
what's your car, po? my guess is, an inline rear wheel drive?
for discussion sake, if you can acquire a concentric low side hose (the inlet to the evaporator wrapped around by the outlet tube), the efficiency of the evaporator is increased. the remaining "cold" of the evaporator outlet tube is allowed to cool the inlet tube. this is similar to recycling the heat or cold. the incoming lower temperature liquid refrigerant temperature is allowed to cool down a bit so by the time it passes through the metering device (orifice tube or expansion valve) it is at an even lower temperature. this is currently done on hybrid and electric vehicles climate control