The IS has been sold as a rear wheel drive and four wheel drive compact car. There have been two generations of the IS and several submodels.
The first generation IS was sold in Japan in 1998 as the Altezza. The car won Car of the Year. The models available at that time were the AS200, RS200, and AS300. The first two were sedans, but the AS300 was a Gita Wagon.
The Lexus IS came to the US and Europe in 2001. It was sold in Europe as a IS200 Sport or IS300 saloon,
while the US got just the IS300. Sales were good at first, with over 20,000 sold in the first year in the US. Those numbers dropped in half in the second year. Europe sales slumped due to the lack of a manual transmission option. The US only got the 6 cylinder engine option, which did not please many buyers.
Because these cars came with an inline 6 engine, they are very popular in the tuning market. The most popular swap is for a Toyota Supra engine.
The second generation started in 2006. It has featured three different V6 engines in three different models: the IS 250, IS 300, and IS 350. In Europe there is also a 4 cylinder diesel model called the IS 220d.
Almost from the start of production of the second generation IS, there were aftermarket parts on the market. This car is the tuning car of modern times.
These cars are all over the used car market if you look in the right places. Demand for them is high, so they don't stay on the market for long. Try checking on eBay for original IS's along with already-modified cars.