Engine wise, i understand ones a cabrio but am i mistaken in believing that most R52 upgrades are R52 compatible?

I have searched

 

I assume you're asking if R53 upgrades are R52 compatible, right?

99% of the time, yes -- although roof racks and roof vinyl graphics don't work too well on the cabrio

The only issue that comes to mind is that some after-market R53, exhaust systems may not work on the cabrio due to the cabrio-specific, under-body bracing. . . so if considering one of those, you may want to look in this forum for brand-specific answers. This bracing also makes the "one-ball" exhaust mod a little more difficult/expensive on the cabrio than on the hardtop.
For the same reasons, rear sway bars are a little more difficult to install on the cabrio (but are compatible -- just a little more work).

Edit -- also, can't use the generic rear-seat delete package.

 

Thats exactly what i was looking for thanks man

 

The cabrio also has a pair of strut braces that are easily installed on the R53. At least any R53 built after 2005. The nuts are already welded in place on all R53 and R50 chassis post 2004.