It really depends what standards u set & what theme/ route u choose & how deep is ur pocket. Every owner has different view & taste, so there is no right or wrong to it.
My advice, priority should be wear & tear part plus ensuring the car is reliable to be driven anywhere, anytime.
Once above has been achieved, then go for cosmetics & performance. Bear in mind, the interior & exterior is 15 yrs old, so it will look tired to certain extent. And then, the million dollar question, what u want, want save the 15 year old leather & paint job or give ur e38 a makeover?
I took the makeover route & I never regretted as I was guided by lots of good friends here.
Kaniz,
You have pointed many good points here. The first to make it reliable and to enjoy the drive is certainly the priority.
Secondly as highlighted I guess whats make you happy,feel good and proud owning this beautiful e38.
I guess I have to really ask myself what will make me happy finally...