I wouldn't call it common. But some foreign car owners do decide to go that route when faced with having to replace an engine that is in short supply in this country in a used form, or one that is far more expensive than this option new. Others buy these cars for peanuts from people who have decided to junk them instead of putting even more money into them. This is the real issue with owning many foreign cars in this country which do not sell in quantity sufficient enough to have numerous dealers and qualified mechanics to work on them. There are only 12 Jaguar dealerships in the state of Florida, and half of them are in the Miami area. There are none at all in half the state including the panhandle. There are only 3 in Alabama. If you don't live in a larger city you have to either find some mechanic who has previous experience working with Jaguars, or you are forced to use someone who has likely never even seen the engine of one before. Their learning experience is likely going to be quite costly. Replacing the engine with an American one solves much of this problem. But it typically introduces many more. Car manufacturers go to great lengths determining the proper weight balance, springs, shocks, and the size and strength of load bearing members and suspension components. If you use an engine that doesn't have essentially the same weight and center of gravity, you will be forced to change a lot of other stuff through trial and error. Or what is even more typical, you will simply ignore it and end up with a car that is far from optimal. It may even be quite unsafe, especially if the brakes are not upgraded to accommodate a far stronger engine than the original.