I dont get it.
Youre first impression should count the most.
Thats it.
Its the first impression thats most important.
The BMW will cost more to maintain, to upgrade and to fix but it will keep its resale way more than the Nissan, it will reward you as a driver more than the Nissan, is built better, uses higher quality materials, is engineered to a different grade and it will attract a different kind of attention.
The Nissan on the other hand will have more power, will be more easily tunable, more able to benefit from upgrades, cheaper to purchase ( that depending on condition ), with hardcore street cred, but will be built to slightly lower standards, wont offer the feedback the BMW will, is showing its age and will show you that its not as solid all round as a BMW build wise.
Trust me on one point.
I have a Forester Sti, have driven and been in a large number of hypo Japanese cars and compared to the many and varied Euros ive driven that include Ferraris, Porsches, Maseratis, Audis, Mercedes and BMW's, i would have to say its lacking in a certain substance.
You can actually feel the solidness of the engineering in a Euro as opposed to a Japanese car. It feels better built, more reliable, offers you a different level of comofort but wont offer the hard core tuning edge and tuning flexibility that the Japanese car will have.
Tough choice but its safe to go with your first impression as long as you have a good go at it when you do drive it for the first time.
Go back for a second bite if youre not sure.