2006 Lincoln Mark Lt

I went over 418,000 miles this morning going to work. Replaced original engine with rebuilt short block at 225,000. Tranny has never been touched. I think more impressive, everything on this truck still works - all steering wheel buttons, back up alarm, power rear window, dvd player, everything. Drivers seat and steering wheel not too pretty these days. I hate to get rid of it, but I drive tons of miles and wondering if I am pushing my luck.