In general, conversions are tough and rather expensive. You gotta find something that looks decent for starters. That in and of itself is tough because there isn't much IMO that WOULD look good. Once you find a decent tail, you gotta hack apart the back of your Sol to get the lamps to fit. Then, fill in and sculpt with body filler/ bondo. Then paint it all. It is a big process to undertake, and is best left to guys who work in a body shop for a living.

Here are a few tail conversions I found on TS....

IS300/Toyota Altezza


Porsche Boxter


Nissan Skyline R33


Toyota MR2