I bought a 40,000 miler k series 111s in July 2000 (53 plate)
I drove it monthly from Hampshire to Norfolk for over 3 years and did not regret one mile of it. Even driving on a motorway was a pleasure and, sitting in traffic, it only took a glance at the logo in the middle of the steering wheel to bring that grin back onto my face.
I still have that car and am going to Club Lotus in it this morning. It now has 122,000 miles on the clock. There is no reason it cannot carry on. There are cars on here with more than 200,000.
The feeling that I get from driving it has not changed. It is a fantastic car! You will see from posts by Exiges and Evora owners that, no matter how good or fast their cars, they respect the ability and sheer fun of an Elise.
The car has not been trouble free. You will have heard about head gaskets and radiators, but once these have been sorted, these cars are relatively low maintenence. But bear in mind that they are low volume, hand made, high performance sports cars and do need looking after.
In my opinion you seriously need to buy one. It is great fun on a motorway it is unbelievable fun on the twisty bits. And youe eyesight will improve looking out for speed cameras (sorry, safety cameras) and gentlemen (and women) wearing blue uniforms.
Buy one. Have fun. You will not regret it.