Nice taste in choices. I, too, am 38 and have the same tastes as you - what I wanted was a cruiser that hauls ass in convertible form (for nice days) So,
1983 500SL AMG:
I would skip the Jag, the Opel, the Volvo, and the SAAB in a heartbeat, but I would very much entertain a 928S4 or a 944/968 Turbo car - both of which better be perfect because they don't seem to age very well (like BMWs).
I always thought the marque that ages the best was the Mercedes - a well-cared for example can still smell new inside and work/feel like new even though it's 25 years old. You should also look at:
1) SEC AMG
2) 500E
3) SL anything (with a hardtop on, they feel like a coupe)
4) BMW 840/850 from the early 90s