Cutlass bursts into reverse but lurches into drive.

First I would check to see if your transmission needs a filter and fluid change. As long as it shifts to all the gears right now you may be able to save it. The trans fluid should have a red color to it if it looks brown its burnt needs to be changed.

May also want to add some Lucas Transmission Fluid.

I'm not sure how a transmission that won't move your car properly can be considered "just fine". That said, save your money. Additives are not going to fix your transmission. As firebird said, check that there is enough fluid in the transmission. If not, fill it with the cheapest transmission fluid available that meets the spec for your car and see what happens. If it starts working properly drive it for a bit to make sure and then service the transmission with fluid and a fresh filter. If filling it up doesn't make the problems go away take it to a reputable transmission shop for a diagnosis. Hope you didn't pay too much for the car. Sounds like it might be a money pit, so be careful.